Watch Glossary

Watch Glossary

Alarm – A function that alerts the wearer at a pre-set time, producing either an audible sound, vibration, or visual signal.

Altimeter – A complication that measures altitude above sea level, commonly found in adventure and aviation watches.

Analog Display – A traditional watch display that shows time using hour and minute hands.

Annual Calendar – A calendar complication that displays the day, date, and month. It automatically accounts for months with 30 or 31 days but requires manual adjustment once a year at the end of February.

Anti-Magnetic – A watch designed to resist magnetic fields from everyday objects such as mobile phones, televisions, and electronic devices, helping maintain accuracy.

Anti-Reflective Coating – A coating applied to the crystal to reduce glare and improve legibility in bright conditions.

Aperture – A small window on the dial, most commonly used to display the date or other calendar functions.

Arabic Numerals – Dial numerals displayed as standard numbers (1, 2, 3, etc.), rather than Roman numerals.

Automatic Winding Movement – A mechanical movement that winds itself through the natural motion of the wearer’s wrist using a rotating rotor.

Balance Spring (Hairspring) – A delicate spring attached to the balance wheel that regulates the oscillation rate, playing a vital role in timekeeping accuracy.

Balance Wheel – A weighted wheel within a mechanical movement that oscillates back and forth to regulate time.

Barrel – A cylindrical component that houses the mainspring. Multiple barrels can increase a watch’s power reserve.

Bezel – The ring surrounding the crystal. Bezels may be fixed or rotating, depending on function.

Bidirectional Bezel – A rotating bezel that can turn in both directions, often used to track elapsed time.

Calendar – A complication that displays date-related information, such as the day or month.

Calibre – A term used to identify a specific movement model and its manufacturer.

Cambered Crystal – A slightly curved crystal that creates a domed appearance.

Case – The main body of the watch that houses the movement.

Case Back – The rear of the watch case that rests against the wrist.

Chronograph – A complication that allows the watch to function as a stopwatch, measuring elapsed time.

Chronometer – A watch that has been independently tested and certified for high accuracy, typically within +6 to -4 seconds per day.

Column Wheel – A component in high-end chronographs that coordinates the start, stop, and reset functions with smooth operation.

Complication – Any function on a watch beyond displaying the time, such as a date window or chronograph.

COSC Certified – Certification by the Swiss Official Chronometer Testing Institute confirming chronometer accuracy standards.

Crown – The knob on the side of the case used to set the time, date, and manually wind mechanical watches.

Crystal – The transparent cover protecting the dial, commonly made from sapphire, mineral glass, or acrylic.

Cyclops – A magnifying lens positioned over the date window to improve readability.

Date Window – A small aperture on the dial displaying the current date.

Day-Date – A complication that displays both the day of the week and the date.

Deployment Buckle – A folding clasp that secures the strap while allowing easy adjustment.

Dial – The face of the watch where time and complications are displayed.

Digital Display – A display that shows time numerically using electronic digits rather than hands.

Diving Watch – A watch designed for underwater use, typically featuring high water resistance, a unidirectional bezel, and a screw-down crown.

DLC (Diamond-Like Carbon) – A durable coating that provides a dark finish with high resistance to scratches and corrosion.

Domed Crystal – A curved crystal that creates a vintage-inspired profile.

Dual Time – A complication that allows two time zones to be displayed simultaneously.

EOL (End of Life Indicator) – A feature indicating a low battery, often shown by a jumping seconds hand.

Escapement – A critical mechanism that transfers energy to the balance wheel and controls time regulation.

ETA Movement – A Swiss-made movement produced by ETA SA, one of the world’s largest movement manufacturers.

Exhibition Case Back – A transparent case back that allows the movement to be viewed.

Flyback Chronograph – A chronograph that can be reset and restarted instantly without stopping first.

Folding Clasp – A clasp that folds over itself to secure the strap.

Frequency – The rate at which a movement oscillates, measured in vibrations per hour (vph).

Gasket – A seal that prevents water and dust from entering the case.

Gear Train – A series of gears that transfers energy from the mainspring to the escapement.

Geneva Stripes – Decorative stripes applied to movement components.

GMT Function – A complication that allows tracking of multiple time zones.

Gold Plated – A thin layer of gold applied over a base metal.

Grand Complication – One of the most complex watch types, combining multiple high-level complications.

Guilloché – Decorative engraving patterns on dials or movements.

Hand-Wound Movement – A mechanical movement that must be manually wound via the crown.

Helium Escape Valve – A valve allowing trapped helium to escape during deep-sea diving.

Hybrid Smartwatch – A watch with traditional hands combined with smart features.

Incabloc Protection System – A shock-protection system safeguarding delicate movement components.

Indices – Markers on the dial indicating time intervals.

Jewels – Synthetic rubies or sapphires used to reduce friction within a movement.

Lap Timer – A chronograph function used to measure separate time intervals.

Lever Escapement – The most common escapement type used in mechanical watches.

Limited Edition – A watch produced in a restricted quantity.

Lugs – Projections that attach the strap or bracelet to the case.

Luminescence – A luminous coating that allows visibility in low light.

Mainplate – The base structure supporting movement components.

Mainspring – The power source of a mechanical watch.

Mechanical Watch – A watch powered by a mainspring rather than a battery.

Mineral Glass – Hardened glass used as a crystal, less scratch-resistant than sapphire.

Minute Repeater – A complication that chimes the time on demand.

Mono-Pusher Chronograph – A chronograph operated by a single button.

Moonphase – A display showing the current phase of the moon.

Movement – The mechanism that powers the watch.

Perpetual Calendar – A complication that automatically accounts for varying month lengths and leap years.

Pin Buckle (Tang Buckle) – A traditional buckle similar to a belt fastening.

Power Reserve – The length of time a watch will run once fully wound.

Pusher – A button used to control chronograph functions.

PVD Coating – A thin, durable coating applied to metal surfaces.

Quartz Movement – A battery-powered movement regulated by a quartz crystal.

Rattrapante (Split Seconds) – A chronograph capable of timing two events simultaneously.

Retrograde Hand – A hand that moves along an arc and snaps back to the start.

Rotating Bezel – A bezel designed to rotate for timing or tracking purposes.

Rotor – A weighted component that winds an automatic movement.

Sapphire Crystal – A highly scratch-resistant crystal second only to diamond in hardness.

Screw-Down Crown – A crown that screws into the case to improve water resistance.

Second Time Zone Indicator – A display showing an additional time zone.

Self-Winding Movement – Another term for an automatic movement.

Shock Absorber – A system designed to protect movement components from impact.

Skeleton Dial – A dial cut away to reveal the movement beneath.

Small Seconds – A sub-dial displaying seconds separately from the main hands.

Smartwatch – A connected watch offering digital features and apps.

Solar Powered – A watch powered by light absorbed through the dial.

Special Edition – A watch created to mark an event or collaboration.

Spring Bar – A metal pin that secures the strap to the lugs.

Subsidiary Dial – A smaller dial within the main dial displaying additional information.

Super-LumiNova – A non-radioactive luminous material used on hands and indices.

Sweeping Seconds Hand – A smooth-moving seconds hand typical of mechanical watches.

Swiss Made – A designation confirming Swiss manufacture standards.

Tachymeter – A scale used with a chronograph to calculate speed.

Tourbillon – A rotating cage that improves accuracy by counteracting gravity.

Unidirectional Bezel – A bezel that rotates in one direction, commonly used on dive watches.

Water Resistance – The measure of a watch’s ability to withstand water pressure.

Worldtimer – A complication displaying all 24 global time zones simultaneously.