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The A-Z watch glossary

Chronometer, hacking seconds, tourbillion! Ever been in a room full of watch fanatics and had no idea what they’re talking about? Yep, me too back in the early days. There’s so much terminology used in the watch world which can get very confusing when you’re just starting out. But never fear, we’re here to help you learn the lingo and speak like a true watch expert with our A-Z guide.

You’re welcome.


Alarm – Unless you live under a rock, this one is pretty straight forward. Its that annoying little thing that wakes you up at 6am. But some watches actually have these built in, like the TAG Heuer Formula 1 WAZ111A. Quite useful as a morning alarm or reminder.

Altimeter – A nifty little watch function that measures altitude, or height above sea level, by responding to changes in barometric pressure. Often used by pilots and other people that want to measure their altitude. You can actually find these features on newer smart watches like the Apple Watch.

Analog display – Probably what the youngsters now know as an old fashioned display, whereby time is displayed “properly” using good old hands and numeral markers rather than using a display screen. Confession: I find digital easier (don’t hurt me).

Aperture – This is a small opening in the dial that displays certain information such as date, day, month or moon-phase. It is quite commonly referred to as a “date window” now though.

Automatic – An automatic watch can also be referred to as a “self-winding” watch or just an “automatic”. The term “automatic” actually refers to the mechanism inside the watch which is mechanical based – or in other words, its not powered by a battery.

An automatic watch is powered by the motion of the wearer’s wrist, a watch winder or other motion. The motion moves a counterweight (also known as a rotor) which then powers the mainspring and gears.

Anti-magnetic – Magnets are bad news for watches. Long story short, it messes everything up! Some watches however have “anti-magnetic” properties that allow them to see off certain levels of magnetic field.

However, its still advised to keep anti-magnetic watches away from magnets as much as possible.

Applied features – When something is applied, i.e. a numeral marker or some other detail, it generally means that it is sitting, raised on the surface of the dial as opposed to being painted on there.

Auto repeat countdown timer – Mostly found on digital watches. This feature is a countdown timer that resets itself and starts again once the present time has elapsed. This happens continuously until the stop button is pushed manually.


Band - When you hear the term “band” you will probably think of a set of guitars, drums and a hot lead singer. But this type of band doesn’t play any music. In fact, its what watch people say when referring to a watch’s bracelet or strap.

Balance spring – Now were getting technical! The balance spring is part of the watch’s internal mechanism and is attached to the balance wheel. It’s a very fine spring that coils and recoils, which in turn causes the balance wheel to oscillate. This then controls the speed that the rest of the wheels in the watch turn and thus regulates time telling. You may hear watch people refer to the balance spring as the hairspring or mainspring.

Balance wheel – Attached to the balance spring, the balance wheel is a weighted wheel that oscillates, dividing time into equal segments. It’s the balance wheel that’s responsible for regulation and timekeeping accuracy.

Basel World – Basel is the epic global trade show for the international watch, jewellery and gem industry. Lots of brands use this to reveal their upcoming timepieces.

Barrel – A drum shaped container that holds the mainspring, housing the watch’s power reserve. The size of the barrel affect the power reserve.

Beat – Again, we’re not talking musically here, we’re talking watch vibrations. The beat is what is referred to when talking about the vibration of a watch’s tick. The sound is produced by the escape wheel striking pallets.

Bezel – Probably one of the first terms you came across when you got into the watch game. The bezel is the ring situated on the top side of the case that surrounds the crystal. We use the term “ring” loosely as they can come in different shapes, such as the 12-sided Aquaracer bezel. Some bezels are fixed, others can move. Some are plain, like the Rolex Milgaus, some include features like tachymeter scales. They can even be made from different materials.

Bi-directional rotating bezel – This is the term used for a bezel that can be rotated both clockwise and anti-clockwise. They are used as timing apparatus as they allow the wearer to quickly calculate how much time has elapsed or how much time is remaining.

Breguet spring - The spiral hairspring on which the balance swings tends to bunch on opposite sides as it expands or contracts. The constant shift in their gravity disturbs the rate of balance, and Breguet solved the problem in 1795 by upraising the last coil of the spring and giving it a smaller curve. This Breguet overcoil encouraged the spring to develop concentrically, improving the rate of the watch and reducing the wear on the balance pivots.

Bridge – You can cross over this one, but it does however fix to the main plate of your watch to form the frame of the movement.


Calendar – Same concept as the one you hang up in your kitchen apart from this one is displayed on the dial of your watch. Some watch calendars only display the date, whereas others can display the day of the week.

Cambered – Sometimes this term is used when referring to a domed crystal.

Caliber/Calibre – We write calibre, we pronounce it cali-ber – whatever makes you happy. The term today Is used to refer to a watch’s movement - specifically the origin/make of the movement.

Case – The case is pretty much the body of the watch. It houses and protects watch’s internals. Cases come in many different shapes, sizes and materials.

Caseback – If you flip your watch over you will see your caseback, or rather your watch’s booty. The caseback is quite important as it’s the part of the watch that actually sits against the skin, so it has to be comfortable. It also makes sure that all of the watch’s internal components don’t fall out! There are different types of case backs such as screw down and snap off. They can also come in different materials and designs, such as the exhibition case back and plain caseback.

Chronograph – A fancy stopwatch. If your watch is equipped with a chronograph, it means that it has an extra feature that is able to measure periods of time as a stopwatch would.

Chronometer - If your watch is classed as a chronometer then you’ve bagged yourself an ultra-precise watch. For a Swiss watch to be classed as a chronometer it needs to have met extremely high standards as set by C.O.S.C. (Controle Officiel Suisse des Chronometres). The watch undergoes vigorous testing which involves measuring the watch’s performance at 3 different temperatures and in 5 different positions for 15 consecutive days.

Mechanical movements that are accurate to -4/+6 seconds per day are awarded a chronometer certificate. Whereas quartz movements must be accurate to +/-0.2 seconds per day.

Complications - A term used to describe the tasks that a watch can perform, these are also known as functions.

Crown – Once described to me as “that thing that sticks out the side of the watch”. Pretty much bang on. The crown is used to wind the watch (if automatic), set the date and time and also ensure that the watch is water resistant/dust proof.

Crowns can come in different shapes, sizes and materials. There are also different types such as screw down crowns and push-in crowns.

Crystal – This is the clear screen that you see on top of the dial. Usually made from either glass, plastic or sapphire crystal. It protects the watch’s dial from external damages.

Cyclops – Some love it, some hate it. Personally I’m a fan, but I also love Jason and the Argonauts… (yes there’s a cyclops in that). A watch’s cyclops is the small lens, attached to the crystal, that magnifies the date.


Day/Date – This is a feature on your watch that shows both the day of the week and the date of the month.

Day/Night indicator – Also known as the AM/

PM indicator. This is a feature that does as it says on the tin, indicated weather you’re looking at time in AM or PM.

Deployment (deployant) buckle – A buckle that attached to both sides of the strap. It opens and closes using hinged extenders.

Dial – Again, probably another one of the first terms you came across when you started getting into watches. The dial is basically the face of the watch. It’s the part that shows us the time. Dials are decorated in many different ways.

Digital watch – Unless you’ve been in bed for the past century I’m pretty sure that you know a digital watch is one that shows the time using a numerical display rather than using hands and numerals like on an analogue watch.

Dive watch – In simple terms, it’s a watch that can be taken diving. However, this requires specific standards to be met. True dive watches have to meet requirements such as being ISO 6425 certified, which requires a watch to be water resistant to at least 200 meters. Dive watches usually feature a uni-directional bezel and lume. A dive watch should not be taken any deeper than its specified meterage.

Dual Time – Also referred to as “GMT” or “second time zone”. Watches with this feature can display time in at least two different time zones. The second time, or even third time zone can be found in a twin dial, extra hand or subdial. A good example of this is the stunning Omega Worldtimer.

Duo Display - A display that shows the time both by hour and minute hands (an analogue display) and by numbers (a digital display). This is also known as AnaDigi display.


Elapsed time rotating bezel - A graduated rotating bezel that is used to keep track of periods of time. The bezel can be rotated so the wearer can align the zero of the bezel with the watch’s minutes or seconds hand. The elapsed time can then be read off the bezel, rather than the wearer having to perform a subtraction necessary if he used the watch’s regular dial.

EOL – This stands for end-of-life battery indicator and is applicable to quartz watches. Once the battery is almost flat the seconds hand will tick once every 4 seconds to indicate that the battery is near to its end of life. This also means its time to get the battery replaced, lucky you.

Escapement - A device in a mechanical watch that controls the motion of the hands by controlling wheel rotation.

Escape wheel - The last wheel in a going train; works with the fork or lever and escapes one pulse at a time.

ETA – ETA is a leading Swiss manufacturer that makes watch movements. You may hear of a watch being referred to as having an “ETA movement”.

Exhibition caseback – The most beautiful of all casebacks (in my opinion). These casebacks are clear, showing off the beautiful watch movement underneath. They are also referred to as skeleton or open casebacks.


Flyback Chronograph - A flyback chronograph is a special type, designed for recording consecutive times such as laps of a speedway. When the flyback button is pressed, the second had flies back to zero and instantly starts counting again.

Function – Seen as though we’ve used this term quite a few times throughout, its probably a good idea to explain what it means? It is a term used to describe the tasks that a watch can perform, these are also known as complications.


Gasket – Otherwise known as an O-ring or rubber washer, watches contain several gaskets; a caseback gasket, a crystal gasket, a bezel gasket and a crown gasket just to name a few. A gasket is a circle of rubber that protect your watch from outside elements getting in such as dust, water, oils and dirt. This helps to prolong the life of your watch and ensures that it works in top condition.

Gear Train – A system of gears that transmit power from the mainspring to the escapement.

GMT – Also referred to as “dual time” or “second time zone”. Watches with this feature can display time in at least two different time zones. The second time, or even third time zone can be found in a twin dial, extra hand or subdial.

Gold plating – This is a very thin layer of gold that is set on top of a base metal (usually steel).

Gradual date change – Whereby the date displayed on the dial changes over a long period of time rather than quickly flicking to the next at midnight.

Guilloche – This is a type of decoration that is usually done to the watch dial or caseback. Lines are engraved into the desired area to make up an intricate geometric pattern.

Grey market – Grey market watches are legitimate products that are sold through an unauthorised source. Watches sold on the grey market do not come with the manufacturer warranty and sometimes even have serial numbers removed.


Hacking seconds – A.K.A “stop seconds”, this feature makes sure that the seconds hand comes to a complete stop when the crown is pulled out fully.

Hand – These ones don’t have five fingers attached – they are those things that point at the hours and minutes to tell you what time it is.

Hand wound – This is a term used when referring to a mechanical watch that doesn’t automatically wind. Hand-wound watches get their power from you manually turning the crown.

Hairspring - Part of the watch’s internal mechanism and is attached to the balance wheel. It’s a very fine spring that coils and recoils, which in turn causes the hairspring to oscillate. This then controls the speed that the rest of the wheels in the watch turn and thus regulates time telling. You may hear watch people refer to the hairspring as the balance spring or mainspring.

Helium escape valve – This does exactly what it says on the tin – it lets helium release from a watch. This feature is usually found on dive watches and used by divers that partake in saturation diving.

Saturation divers spend long periods of time in decompression chambers, where the gas mixture they breathe is 95% helium.

As helium molecules are so tiny, they have the ability to get inside of a watch. When this happens, the pressure inside the watch then becomes the same as that inside the pressurised diving chamber. When the diver has to resurface and return to normal atmospheric pressure, the gas cannot always escape from the watch. This results in excess internal pressure and causes damage to the watch.

However, escapement valves provide a solution to this as they allow the gas trapped inside to escape safely without damaging the watch.

Hesalite – An advanced form of acrylic used instead of glass or sapphire crystal to protect the watch dial. Notably used on the Omega Speedmaster Moonwatch.

Horology – The art/science of measuring time.

Hour markers – Usually Arabic numerals, sometimes Roman numerals, sometimes crazy symbols. As long as they indicate what hour it is, it passes.


Indices – This is another wat to refer to the watch’s hour markers. We also use it to refer to minute markers.


Jewels – Synthetic gemstones that reduce friction between the metal components of the watch.

Jumping hour/minutes – As the hands of a normal watch would slowly sweep around the dial as time passes, jumping hour/minute hands instead point exactly to the current hour/minute and suddenly jump to the next hour/minute.


Lap timer – This watch feature allows the wearer to time race segments.

Lever escapement - The lever divides into two pallets which lock and unlock the escape wheel teeth. The action is governed by the balance engaging the other end of the lever, the escape teeth sliding on the inclined pallets lift the lever to impulse the balance.

LCD – Short for liquid crystal display, where a watch’s display is shown through the means of a liquid layer held in between two transparent plates. We find them on digital watches.

Lugs – These are the bits of metal that protrude from the watch case. The strap attaches to them. The two ends of the lugs are there to hold the spring bar, which the strap attaches to.

Lume - The numerals and hands on luxury watch dials are often treated with a luminous glowing solution. This is what makes your watch glow in the dark.


Main plate – The base plate upon which all of the other parts of the watch movement are mounted.

Mainspring - The mainspring is part of the watch’s internal mechanism and is attached to the balance wheel. It’s a very fine spring that coils and recoils, which in turn causes the balance wheel to oscillate. This then controls the speed that the rest of the wheels in the watch turn and thus regulates time telling. You may hear watch people refer to the mainspring as the hairspring or balance spring.

Manual-wind movement - This is a term used when referring to a mechanical watch that doesn’t automatically wind. Manually wound watches get their power from you turning the crown by hand.

Measurement conversion – This feature allows the wearer to convert one type of measurement into another; usually via a graduated scaled on the bezel or dial.

Mechanical movement – Used mostly when referring to a watch that runs without an electrical source, where the watch’s mechanism is made up of mechanical parts such as gears and screws etc.

Military time – Otherwise known as twenty four hour clock where the time is referred to as 13:00, 14:00 etc.

Mineral crystal – This is a heat hardened glass.

Minute repeater – A feature that allows the watch to chime out the time.

Moonphase – These are beautiful. They are displays on watches that show the different phases of the moon throughout the course of the month.

Mother of pearl – Otherwise shortened to “MOP”, this is a material that is used in watch dials. The material is found in the outer coating of a pearl (hence the name). It is usually an iridescent shade of white.

Movement – Basically, the engine of the watch that allows it to function. Watches can have automatic movements, manual movements or quartz movement.


Numerals – The same as indices (see above).


Perlage – This is a beautiful cloud-like decoration on plated and bridges of a watch.

Perpetual calendar – A function that shows the date, day of the week and month. Some will also display the year and moon phase.

Power reserve indicator – This is sometimes used on mechanical watches to indicate how much power is left in the watch movement and how much time you have left until your watch needs to be wound again.

Pulsimeter – A scale on a chronograph used for measuring pulse rate. Now commonly found on smart watches.

Pusher – The buttons that stick out the side of a watch’s case that enable certain functions; including chronographs, alarms, date correctors and more.

Push/pull crown – A crown that just simply pulls and pushes in and out.

PVD – Short for physical vapour deposition, this is a thin coating that’s applied to a case to add colour and in some cases durability.


Quartz movement – In basic terms, this is a watch movement that uses a battery as its primary power source.

Quick set – Also referred to as a “quick date” feature, this allows the wearer to quickly change the date displayed on a watch without having to manually turn the hands past midnight.


Rattrapante – See “split seconds”

Regulator – This is part of the watch’s movement that regulates the watch’s beats by either slowing them down or speeding them up.

Repeater – See “minute repeater”.

Retrograde – Instead of showing time in a circular fashion, as we are traditionally used to, retrograde watches instead display time in a linear format. The hands will move along in an arch and then jump back to the beginning.

Rotating bezel – Whereby the bezel can be rotated.

Rotor – Found in automatic watches, these pieces rotate when the watch is being worn which winds up the mainspring and gives the watch its power.


Sapphire crystal – A synthetic material used to top the watch and protect the dial, sapphire crystals are extremely strong and scratch resistant.

Screw down crown – Rather than a push/pull crown, a screw crown is threaded and tightens to the case by screwing the crown into a threaded tube that is part of the case. This ensures more water resistance.

Second time zone – see “GMT”.

Shock absorber – A bearing inside a watch that is used to take the impact of any shocks received by the watch’s balance staff and protects its pivots from damage.

Skeleton – Used to refer to a watch whereby its inner workings are visible, either by the caseback or dial.

Slide rule - A rotating bezel that can multiply or divide two numbers, convert miles/KM, convert exchange rates, etc. An example is a dollar to Euro converter to calculate rate of descent or fuel consumption for pilots.

Small seconds – A small sub-dial that displays the seconds hand, rather than having a big long seconds hand as part of the main dial.

Solar watch – Usually a quartz watch that can be charged through solar panels on the watch.

Split seconds – A Chronograph with two centre seconds hands, the extra hand runs concurrently with the main chronograph hand but can be stopped independently then made to catch up with the running chronograph. Thus called the “Split Seconds hand” which refers to two hands – a flyback (Rattrapante) hand and a regular chronograph hand.

Both hands move together with the ability to time laps or multiple finishing times, the wearer can stop the flyback hand while the chronograph hand continues. This, in effect, splits the hand in two. The split seconds thus allows recording the successive or additional times of events that start together.

Spring bar – This is a spring loaded metal bar that sits between the lugs. It is used to attach the strap to the case.

Stainless steel – The majority of watches use steel as their base metal as stainless steel is durable, almost rust resistant and rarely corrodes or discolours.

Stem – The shaft that connects the crown to the watch’s winding mechanism.

Strap – See “band”.

Sub dial – Smaller, separate dials placed inside the main dial. Sub dials display additional information such as chronographs, alarms and calendars.

Sun/Moon indicator – A watch complication that indicates the sun and moon over the course of the day.

Sweeping seconds – This is where the seconds hand moves in a sweeping motion rather than a stop/start ticking motion. Usually only mechanical watches sweep, whereas quartz watches tick.

Swiss A.O.S.C – A mark that signifies a watch has been assembled in Switzerland and contains components of Swiss origin.

Swiss made – You may have seen this written on your watch’s dial somewhere. Swiss watches have a reputation for being of the highest quality but a watch can only be considered as Swiss made if:

1) Its movement is Swiss

2) Its movement was cased up in Switzerland

3) The manufacturer carries out final inspections in Switzerland.


Tachymeter/Tachometer – A tachymeter scale is usually engraved or printed onto the bezel of a watch. It is primarily used to measure speed, but can also be used to measure other things too.

Tang buckle – This is a traditional loop and pin buckle.

Telemeter - A telemeter determines the distance of an object from the observer by measuring how long it takes sound to travel that distance. For example, determining the distance of a storm from its observer. The wearer starts the chronograph at the instant the flash of lighting is seen, then stops it when thunder is heard. A reading can then be taken to determine the distance of the storm from the observer in miles on the telemeter scale.

Titanium – A metal used in quite a few watches these days due to the fact that it is stronger and lighter than steel.

Tonneau – This tern refers to a watch that has a case shaped a bit like a barrel, with two convex sides.

Totaliser – Often seen as a sub-dial, this function keeps track of and displays elapsed time.

Tourbillion – This is a mechanism that used to increase the accuracy of a watch by countering the effects of gravity on the balance spring. Usually these are found in very high end watches as a way of showcasing the manufacturer’s watchmaking abilities.


Uni-directional rotating bezel - This is the term used for a bezel that can be rotated only in one direction. This type of bezel is often found on diving watches and often have a fail-safe feature which means the diver cannot overestimate remaining air supply.


Vibrations – Not the sort of vibrations that your watch gives you, but rather the vibrations of the balance wheel. A watch’s frequency is measured using two different terms: hertz (Hz) and vibrations per hour (VpG). One vibration is a single swing of the balance wheel.


Watch winder – These can look pretty swanky sat on your bedside table. They are used to keep automatic watches running when they are not being worn.

Water resistance – A watch that is water resistant can withstand a specified amount of water. Not to be confused with waterproof! Also important to remember that a watch’s water resistance rating will not last forever. It is important to have the water resistance rating of a watch tested regularly

Winding – This is when you give the watch its power either by twisting the crown in its “winding position” or putting it into a watch winder if it’s an automatic watch.

World time – This is a dial that tells the time of up to 24 time zones around the world. The most notable of which is the Omega Worldtimer watch.


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