• 100 days best price guarantee
  • 30 days right of return
  • Free delivery for orders exceeding 40 €
  • 24h express shipping
  • 100 days best price guarantee

watches-dictionary terms and definitions around the clock

a b c d e m o p q r s t w y



Mornings or before lunch or after midnight. Whatever way you want to look at it, in any case the first 12 hours in a day or - to be more specific - the time between 00:00:00 and 11:59:59. A.m. stands for ante meridiem, which is latin for ´before midday´.


Your need to wear a watch or hanging a clock on your wall is probably driven by one or two reasons: you need to know the time and/or it looks good. The looking good part is a question of taste, and tastes vary. Time doesn’t vary. So accuracy is fairly important, but how is it measured? There are different certificates out there for all kinds of watches. Listing them all here would fill our hard-drives so I will limit it to what we can expect from the most common watch types. Automatic watches are driven by a mainspring a lot of little cogs and wheels. Even the most precise mechanics will have some leeway and all these bits and parts clicking and sliding on each other will have some wear after a while. An automatic watch or clock should have an accuracy of no greater than +/- 30 sec. per day. Your automatic watch doesn’t stay within these limits? Don’t despair! Because they always have some leeway and are subject to wearing down of the parts, they can be calibrated to bring them back on track. Your local watchmaker or the watches manufacturer will be able to do this for you. Quartz movements are the most commonly used movements in watches today. This is because of their low manufacturing costs and high accuracy. A quartz watch should not lose or gain more than 30 seconds a month. So almost all watches need regular synchronisation, even atomic clocks. That is why they are usually connected within a network of atomic clocks, so that they can constantly compare themselves with each other, because your average atomic clock can go wrong about a second ever 30 million years, you know.


An analogue watch or clock is a timepiece that has the time intervals such as hours and minutes / seconds on its face permanently. The current time is indicated by some form of pointer, most commonly a rotating finger.


The anchor is an escapement used in pendulum clocks. Also called recoil escapement, it allows the clocks drive to move forward a fixed amount with each swing of the pendulum. It looks like an upside-down anchor and is fixed to the top of the pendulum. With each swing, one of the “anchors” ends, will release a tooth of the so called escape wheel, while the other end will halt the escape wheel a short time later, as the pendulum continues to swing. The anchor escapement has been replaced by the more accurate deadbeat escapement in almost all modern pendulum clocks.

Atomic Clock

Besides being the name of the best online shop for watches and jewellery, it is also the general name for the most accurate clocks available to mankind. Atomic clocks measure the frequency in which the electrons of an atom change their energy level. Whenever this happens, the electrons emit energy which can be measured by a microwave, optical or ultraviolet receiver. As these changes in energy levels are always constant at the same temperature, they are a perfect subsidy to the pendulum of your old grandfather’s clock at home. One more thing: atomic clocks are quite large, too large to strap to your arm, and too high-tech for you or me to put on our bedside table or hang from the kitchen wall. These watches and clocks are frequently referred to as atomic clocks / watches, but are in fact radio controlled ones.


Auto-quartz watches use the mechanical properties of an automatic watch to power a quartz watch drive. Developed and used by the Japanese watchmaker Seiko, who stylishly call it the Kinetic Drive. As with automatic watches, the auto-quartz watch incorporates an imbalanced rotary that uses the wearers movements and the miracle of physics (mass mechanics, to be specific) to electronically drive a quartz movement. Why go to all this trouble? Auto-quartz watches combine the advantage of not having to open the watch for battery changes with the accuracy of a quartz watch. Not convinced yet? Seiko have added their “at-rest” feature to the equation: even if the watch is motionless and loses its energy, it will remember the time and re-set itself to the current time once the juice comes back. And it can do this up to four years of lying around uselessly!

Automatic watch

Automatic watches are mechanical wrist watches that have an imbalanced rotary attached to the mainspring. This rotary moves through the movement of the watch wearer and the mechanics of mass. A sliding clutch stops the mainspring from overwinding, should it already be wound up to the max, but the watch just keeps getting moved around. Automatic watches should ideally always have a little force on the mainspring. That is why true watch aficionados that may have several watches and might not wear one for a while will keep their automatic watches in an automatic watch winder. More on that under watch winders. A small note of advice: automatic does not necessarily mean that this watch never has to be wound up manually (usually by turning the crown). When a new automatic watch is obtained, it generally needs to be wound up first by hand. As the watch is “charged” by movement, it also depends on how much you move while wearing the watch. A professional juggler for example, will never have to manually wind his automatic watch up. But if you are one of these silver painted robot-people that stand around motionless for hours in metropolitan pedestrian zones, then you will probably have to do so on a regular basis.


Baguette movement

The Baguette movement, also called skeleton movement, is a particularly slim drive that is often used in dainty little ladies watches. The wheelwork is arranged on two closely fitted levels.

Balance wheel

The balance wheel of a movement delivers the timebase to which it will tic-toc-tic. The precision with which it is set will determine the accuracy of the clockwork. So just in case you meet a watchmaker who admits that balance wheels aren’t really his thing, you might want to think twice before letting him fiddle with your timepiece.


As a mechanical watch is made of many little parts, all moving at different speeds, and this causes friction and wear over time, bearings are a vital aspect of a clockworks inner life. Many high-quality watchmakers use small gemstones that are so hard they can withstand the constant rubbing on each other and on metal. Rubies are often used. As these bearings last much longer than their metal counterparts, the clock or watch work can last for years on end without having to be overhauled, and still work perfectly.


The bezel, which is sometimes called a lunette, is a part of the watches casing. It consists of a metal ring with a groove in it, that is placed around the watch glass. There are fixed bezels and screw bezels, which can be used to measure certain figures. For example divers watches tend to have a screw bezel with which the diver can set his diving time. Other bezels for example on pilot’s watches can be used to navigate, measure speed or how much fuel is left. Sometimes the bezel has no practical function, but is just used to make the watch look flashy.

Binary watch

Binary watches display the time in the unorthodox and slightly nerdy manner of binary numbers. This requires some basic maths skills and the knowledge how the binary system goes: 1 2 4 8 16 32 (that’s sufficent for a watch). The watch will now indicate - by an LED in most cases - which of these numbers you need to add up, much like in the same way a computer reads a number: 01001:110001, for example. The ones indicate the numbers you need to add up, the zeroes are ignored: 01001 = 1 2 4 8 16 = 2 + 16 = 18 (or 6 p.m.) and 110001 = 1 2 4 8 16 32 = 1 + 2 + 32 = 35 minutes. Ergo: 6:35 p.m. in our case.



A frequently used gemstone. Instead of your usual cut diamond faceting, a cabochon will be shaped and polished to a more round appearance. They are often used on the crown of a watch.


The caliber in horology used to describe the size of the movement used, much like the size of a firearms bullet is described by caliber. Nowadays the caliber describes the exact movement built into a watch. The caliber is registered with the Federation of the Swiss Watch Industry, of course (nothing is worth anything unless the Swiss say so when it comes to watches). The caliber is also important in combating the sale of fake watches and must be mentioned on any export invoice with the coordinated international Custom’s code, according to the World Trading Organisation’s rules for Customs and Excise.


A chronograph is a stop watch. Most wristwatches that incorporate a stop watch are also called chronographs, but this is just because it sounds more fashionable, in reality they are still wrist watches that incorporate a chronograph. The word chronograph comes from the ancient Greek word “chronos”, meaning time and “graphein”, to write. So in effect it’s a time-writer. Chronographs are not to be mixed up with chronometers. They are something completely different, which will be explained in the bit about…


Chronometers are very precise timepieces. “Chronos” is ancient Greek for time (which you will already know if you read the bit about chronographs) and “metron” is to measure. So it’s a time measurement. Not to be mistaken for a chronograph, a chronometer will not necessarily have a stop watch function. Chronographs come from a time before quartz movements. A time where the second was of little importance to the small man. But as irrelevant as it might have seemed to the plebs, exact timekeeping was of great importance to anyone needing to navigate before GPS was invented. The navy and early aviators relied on these exact chronometers to successfully navigate their vessels. Now a chronometer is often used to describe a relatively precise timepiece. But to officially call your watch a chronometer, a lot more has to be done. The watch has to undergo a standardised testing by either an observatory or an official body of movement inspection. As you can imagine, it is the Swiss who set the rules. More specific, it is the independent Swiss observatory: Contrôle officiel suisse des chronomètres (COSC). Only when a watch has received the prestigious COSC-certificate, the manufacturer may brandish the chronometer inscription. As the calibration and necessary testing have been standardised (ISO 3159), authorised testing facilities have crept up in several other countries that seem they would have something like that (Germany for example). The testing of an automatic watch takes 15 days, during which the watch must lie in different positions and at different temperatures, while staying within the certificated strict regulations. We think that people who like very precise watches would also enjoy very strict regulations, so its a win-win situation.

Countdown alarm

Not surprisingly it is an alarm that will count backwards until it reaches zero. So instead of setting it to a certain time then, you can set it to go off in a certain amount of time staring from now.



Digital watches and clocks have a digital display. That is what makes them digital watches and clocks. Whether they record time in a digital or analogue fashion is irrelevant. A digital display will not point out the current time on a display of all times possible, as it does in an analogue watch, but it will only show the digits of one time. Nowadays this usually happens via LED or LCD display, but that has not always been the case. Digital watches have been around long before the electronic display was invented. They used turning disks or cylinders behind a mask that would only show one digit at a time. Or airport-style flip-card mechanics were used.

Divers watch

If you consider that divers rely on a good watch in order not to die, one could expect designated divers watches to be quite robust timepieces. In Germany, where we are based, a divers watch has to fulfill certain criteria before being allowed to be called a divers watch. These watches are usually watertight to a pressure of 20 bar and over. They are also fitted with large indexes and fingers so that they are easy to read through your goggles in the dim light of the deep blue sea at a distance of at least 25 cm. They will also have to have a timer or a bezel which can be turned to indicate the time a diver needs to consider when calculating the remaining oxygen in his or her tank and to keep the intervals needed when ascending back to the surface. This bezel can only be turned one way so as to eliminate the possibility of it being moved by accident, increasing the diving time over the oxygen supply and thus causing a horrible death through drowning.



Quartz movements are all fine and dandy, with their incredible precision and reliability, until the moment their battery drive runs out of electricity. Then they cannot just be wound up, they have to be opened and a new battery needs to be installed. Depending on the class of water resistance you are aiming for this can require some quite sophisticated equipment you will not have in your shed at home. So the clever lads over at Citizen set out to solve that problem and came up with their Eco-Drive. By harnessing the solar power and converting it into energy, which is stored by a small rechargeable battery. Then they combined this with incredibly sophisticated and energy efficient movements, which seem to use up next to nothing and voila: a quartz watch which never needs a battery again. In fact the movement uses up so little energy that a fully charged Citizen Eco-Drive watch will last up to three years in complete darkness before stopping.


An escapement is a part in a mechanical watch that controls the amount of power coming from the power reserve (check out power reserve if you please). Without an escapement the entire tension of the wound up mainspring or the weights in a grandfather clock, would be unleashed all at once, causing the entire clockwork to start spinning like mad until the mainspring is unwound or the weights go crashing into the floor. There are many different types of escapements, for example the anchor or deadbeat escapement. By the way: the ticking you hear in a watch, that’s the escapement.


Manual winding

Mechanical watches receive the energy for their movements by a mainspring that is put under tension. This can be helped by an automatic winding mechanism (see automatic watches), but even these watches need to be wound up manually every now and again. Some watches and clocks can be wound up by using a little winding key, but more commonly it is done by turning the crown that you can also set the watch with.

Mechanical watches

A watch that uses the power of a wound up mainspring to drive a non-electrical movement.

Mineral glass

A watch glass (or crystal) is one of the most exposed parts of a wrist watch. When men in suits and stove pipe hats fished a fancy little pocket watch from their frocks and flipped a lid to get a look at the watches face, normal glass was quite all right as it was protected. Then came the wristwatch and things changed. The wristwatch is constantly subjected to the wearers surroundings and will receive quite a lot of bumps and the occasional hard object being scraped across its glass. This is why most watch manufacturers offer their watches with an especially hardened mineral glass, which will withstand most every day abuse a watch is bound to get and stay clear and unscratched for much longer than an ordinary glass.

Motion work

This part of the watch will also be called dial train and consists of the quarter pipe, which drives the minute hand, the hour wheel, which drives the hour hand and a change gear which connects the two, so that they run at a ratio of exactly 1:12. It is the part which connects the watches movement with the actual hands that show the time. Nowadays a mechanical watch will usually have a second hand which makes the addition of another wheel necessary. This will be the so called central second.


Officers clock

Officers clocks are the first kind of travel alarm clocks, which first came up in the early 18th century. Usually in a brass casing that could be opened and folded to make a stand and sometimes fitted with an alarm bell.



The last 12 hours in a day. Short for post meridiem, which a 2000 year old Roman would say to after midday.


Pendulum clocks use a weight (called bob) on a shaft, which swings back and forth in a precise time interval. This is done to keep the time interval by operating an escapement (look at escapement to find out what that is), which regulates the speed of the clockwork. Because this pendulum is subject to influences such as air pressure, humidity and temperature and gravity (yes, gravity is correct. If you have been working in the reception of your company’s skyscraper and are promoted to a top floor desk, by marrying your bosses offspring perhaps, your pendulum clock will noticeably loose time due to the reduced gravity in greater height.), you will need to adjust the position of the bob to compensate and keep the ticking intervals exactly one second apart.

Perpetual calendar

A perpetual calendar is a calendar that will give you the day of the week at any date in any year. So it would tell you for example that January the 11th in 2023 is a Wednesday. This works because the only part of the day and date never repeats itself: the year. Days, weeks, months all keep repeating themselves throughout their cycle. This can be used to fit a calendar into a watch that will continue to proceed through these cycles and never run out. Plus it gives you the day of the week.


As wristwatches are usually attached to people and people tend to move, the watch will be held at different angles while in use. So the watch needs to function in all kinds of postures and run at the same speed. A normal clock will not be manhandled quite as much and can be built to function in one particular posture. Traditionally there are five postures that watches tested in: “Crown left”, “crown up”, “crown down”, “face up” and “face down”.

Power reserve

Actio et reactio. For a watch to tick, it needs some source of energy to drive the movement. But do you want to be constantly turning the crown of your watch, or have a cable powered one on your wrist? Nope, we don’t either. So we need some kind of power reserve to store the energy needed by the watch to continue ticking for a while. This will be batteries in electronic watches, tension on the mainspring in mechanical ones, weights in big old grandfather clocks. Different watches will use up more or less energy. Chronographs will use more to drive the stop watch. Date displays, radio controlled watches, GPS receivers, heart frequency monitors and all kind of gadgets you can find in old and new watches all use up energy. Generally you can say: the more your watch is capable of doing, the shorter it will run on its power reserve.


It measures your pulse, the frequency your heart beats in. A feature a lot of the new sports watches have. Some are even combined with a GPS tracker and a computer interface. So you can measure and plan a training routine with a surprisingly high level of professionalism. So get off your couch. No more excuses!



Fun fact: even though quartz is only the second most abundant mineral found in our earths crust after feldspar, quartz watches are clearly the dominantly found timepieces on wrists of people walking on our crusty earth. Ha, take that feldspar! But seriously, electric clock movements using quartz oscillators were invented in the late 50’s by Japanese people in white lab coats. They then kept going on developing smaller portable versions until they could be fit in a wrist watch. Quartz watches are not only cheaper in production than mechanical watches, but they are also at least 10 times as accurate. A quartz watch should not lose more than a second a day. This is because a quartz crystal is used as an oscillator that stably reverberates at a certain frequency. For a more accurate account of accuracy, please read the bit about accuracy.


Radio controlled watch

Radio controlled watches and clocks are timepieces that are able to receive a radio transmitted time signal and set themselves to it. They are what you and me can use to benefit from these incredibly exact atomic clocks out there. There are many different time signals, most countries have their own, so lets get technical: There is the MSF signal, also known as “Rugby Clock”, which broadcasts at a frequency of 60 kHz from the Anthorn radio station in Cumbria at a signal strength of 17 kW. The effective range is approx. 1000 km, so it will be received throughout the UK and western Europe. There are three atomic clocks on site, operated by the National Physical Laboratory. The information in the signal includes the UTC (former GMT) year, month, day of month, day of week, hour, minute, British Summer Time. The other commonly used radio time signal broadcast in Europe is the DCF77. This is broadcast from Mainflingen, near Frankfurt/Germany. So it is placed pretty centrally in Europe. It is transmitted at 77.5 kHz with a relatively high power of 50 kW, which means it has an effective range of 2000+ km. The signal contains pretty much the same information that the UK MSF signal does, but in UTC+1 (or CET). It is widely used in Europe because of its strength and centrally located broadcasting station. It is also quite popular in the UK, as almost all radio controlled watches can be set to a different time zone. This means they will still receive the DCF77 signal, but then add or subtract the amount of hours according to which time zone they have been set to. There are multi-frequency watches available. These watches will be able to receive different time signals on different frequencies. Apart from the UK’s MSF and the European DCF77, the most common ones are the US WWVB (60 kHz) and the Japanese JJY (40 kHz and 60 kHz). It is very important to know that the radio signal and the reception thereof is subject to various conditions. Apart from the fact that the signal does not mix that well with thick concrete and steel buildings, the time of day and the weather play a huge role. Rain will lower the range, but the signal will bounce off clouds, amplifying it a bit. The signal can travel further at nights and even the time of year and the position of the moon can have a slight impact. It has happened, that radio controlled clocks in eastern Canada set themselves regularly to the German DFC77 signal. It can also happen that you will have problems receiving the signal in the middle of England. Most commonly it is a too weak battery, but you could live in a valley or behind a mountain or just a massive building. If you are having problems receiving a radio signal, place it on the windowsill over night, preferably in the direction of the broadcasting station which signal you are trying to receive. If this does not work, turning the watch by 45° might do the trick. Sounds like a lot of witchcraft? Well, radio controlled watches are a lot more technical and tricky than normal ones. A perfect every-day reception is by no way guaranteed by the manufacturers. And it is not really required as the watches only use the signal to set their highly accurate quartz movements. Unless you calculate time in milliseconds, a couple of days without a signal will pass unnoticed.

Rapid ascent warning alarm

The rapid ascent warning alarm rings as the watch detects ascent equivalent to 9m per minute.

Roman numerals

1 = I, 2 = II, 3 = III, 4 = IV, 5 = V, 6 = VI, 7 = VII, 8 = VIII, 9 = IX, 10 = X, 11 = XI, 12 = XII



The most robust watch crystals are made out of sapphire glass. Only diamonds and carbide is harder and can scratch sapphire glass. Of course there are other materials such as some metals and stones which will scratch your sapphire glass crystal, so it is not wise to expect the watch to handle any abuse without getting marked. Sapphire has one downside though, it is highly reflective. Some watches receive an anti-glare coating to compensate for this, but sadly this coating is less hard and will scratch more easily.

Screw in crown

Normally you will be able to pull out a crown just like that, but some watches are fitted with a screw in crown. This means that the crown is fitted with thread that you can screw the crown tightly into the watches case. Even though watchmakers have devised different methods of making a watch watertight, a screw in crown is still seen on a lot of watches, as it also stops you from pulling out the crown and changing the time and date by mistake.

Small Second

A small second is a sub dial on the face of the watch that shows the seconds separately, instead of having a seconds hand on the same axis as the hour and minute indicator. Usually the small second is positioned above the “6”.

Swiss made

Switzerland is famous for cheese, chocolate, banks and timepieces. The country has a long tradition in clock making and many of the most sought after watches are made here. Of course the Swiss are not only very precise in their timekeeping, they also like to make rules. To be able to be called “Swiss made” certain criteria have to be met. The movement has to be put together, set to work and regulated and checked by the manufacturer in Switzerland. Furthermore at least 50% of the components have to be made by Swiss manufactures meeting the high standards there. And these Standards are very high. It comes of no surprise that the Swiss are famed world over for their watch making skills.



This is a device with which the speed of an objects movement can be measured. Some watches sport a tachymeter scale on their face. It will tell you directly how fast something was by showing how much time has passed in which the object had to travel a pre-defined distance.

Telemeter scale

Some chronographs sport an additional telemeter scale. This scale can be used to measure the distance by the time taken for a sound to reach the observer. To do this you measure the time between something happening (yes I know, light does take some time to reach you as well, but lets not split hairs) and the sound reaching you. Like you learned to calculate the distance of a lightning strike, by counting down the seconds between the flash and thundering roar.

Time zones

Since the going theory stipulates that the earth is not flat and the sun is not the sun-god Ra in his golden chariot, but that we actually live on a ball of dirt flying around a star, it is obvious that the daytime will never be the same on any two points of different longitude at any given time. Now if you were going to be precise, then you are actually in a different time of day than your neighbours to the east and west of you. But that would be splitting hairs, or would it? Anyways, important people decided a long time ago that for practicalities sake, they would divide the globe into 24 time zones that are one hour apart. Of course one had to find a compromise between geographical position and national borders in order for ordinary life to function. Since the industrial revolution, people adhering to the same principles of time measurement have become essential to the workings of our society. But you will find that every so often a time zone will shift in order to make life easier or more profitable in one country or region. For example the UK is considering not of moving to a different time zone, that would be rubbish of course, since they invented it, but of adopting “double summer time” in one year and then only going back one hour at the end of it. This would effectively put them in the same time zone as the rest of Europe.


Different from titan watches, which are just timepieces for very large people out of the Greek mythology, titanium watches are made from titanium. This is a very hard metal, making the watches very durable and scratch resistant. Plus this metal is surprisingly light, so titanium watches will not dislocate your shoulder every time you swing your arm. It is these to qualities that make titanium popular with space technology engineers, racing car makers and other high-end gadgetry. In addition to being just a very suitable material for making watches out of, it is also the case material of choice for people with a nickel allergy who have too much style for plastic watches. Titanium watches definitely do not contain nickel. Titanium is also darker than stainless steel. It looks greyer and is less shiny than the silvery gleam of stainless steel watches.


Tonneau is French and describes a barrel-shaped watch case with long, straight sides and rounded top and bottom ends.

Torsion pendulum clocks

Torsion pendulum clocks are mechanical clocks that use a pendulum rotating around its axis. You will quickly recognise them by the kind of cheese dome they are usually put under. This is because they are very sensitive to changes in temperature and air pressure. So why bother? Because some people think they look good, and more importantly they are incredibly energy efficient. Sometimes referred to as year-clocks they are able to run up to a whole year on one winding.


Water tightness

Water tightness or impermeability, surprisingly enough, is the degree to which you can expose your watch to the element water. A watch can be water repellent to a variety of degrees, from surviving the odd splash, to keeping the watch fully functioning long after your crushed body has hit the ocean floor. Please note that these are always theoretical values. Water behaves very differently at different temperatures and with varying salinity. So we took our crayons and made you this rough guide (which, by the way, is in no way legally binding and we will not be held accountable for your watch if you ruin it): Waterproof FYI: 10m is 1 bar is (roughly) 33 ft is (exactly) 0.986923267 atm


Yacht timer

Ahoy! If you have a yacht or like to pretend to own a yacht, you might want to have a look at getting yourself a so called yacht timer. These are watches that feature some special functions you might find handy on a boat. These functions might include a 10 minute countdown for regatta racers, tidal tables and even a GPS signal triggered anchoring alarm which goes off when your position moves. Of course yacht timers are water resistant to a pressure of at least 10 bar, because that is what you will need when the going gets tough.

Uhrzeit.org uses cookies both to implement essential shop functions and to measure user behaviour on our pages and to offer content relevant to the user and personalised advertising on our and third-party pages.
If you do not agree to this, please specify your preferences via 'Settings'.