Accuracy: The measure of how well a timepiece keeps time.

Alloy: A mixture of two or more metals used to create a specific material with desired properties.

Amplitude: The extent of the swing of a balance wheel in a mechanical watch.

Analog: A traditional method of displaying time using hour, minute, and sometimes second hands on a dial.

Anti-Magnetic: A feature that protects a watch movement from the effects of magnetic fields.

Aperture: An opening on the dial that displays additional information, such as a date or moon phase.

Art Deco: A design style popular in the 1920s and 1930s known for its geometric shapes and bold colors.

Automatic Movement: A self-winding mechanical movement that uses the natural motion of the wearer's wrist to power the watch.

Aventurine: A type of glass or quartz with sparkling inclusions, often used in dials or watch decorations.

Accuracy: The measure of how well a timepiece keeps time.

Astronomical Watch: A watch that displays astronomical information, such as moon phases, tidal movements, or celestial events.

Altimeter: A feature that measures altitude or height above sea level.

Alarm: A function that allows a watch to emit an audible sound at a pre-set time.

Anti-Reflective Coating: A thin layer applied to the watch crystal to reduce reflections and improve visibility.

Arabic Numerals: Number markers on a watch dial represented by the Arabic numeral system (1, 2, 3, etc.).

Articulated Lugs: Lugs that are designed to move or pivot, allowing the watch to better conform to the wearer's wrist.

Acrylic Crystal: A transparent plastic material used as a watch crystal that is lightweight and impact-resistant.

Annual Calendar: A calendar complication that automatically adjusts for months with 30 or 31 days but requires manual adjustment for February.

Astrolabe: An ancient astronomical instrument used for measuring time and determining celestial positions.

Anti-Shock System: A mechanism in a watch movement that protects the delicate parts from the impact of shocks and vibrations.

Automatic Chronograph: A self-winding watch with a chronograph function that measures elapsed time.

Auxiliary Dial: A small sub-dial on a watch that displays additional information, such as a second time zone or a power reserve indicator.

Astronomical Complication: A highly complex watch complication that displays astronomical information, such as the positions of celestial bodies or the equation of time.

Artistic Craftsmanship: Decorative techniques applied to watch dials, cases, or movements to enhance their aesthetic appeal.

Adjustment: The process of regulating the movement of a watch to ensure its accuracy.

Aloha Time: The time difference between Hawaii and Coordinated Universal Time (UTC-10:00).

Anti-Reflection Coating: A thin coating applied to the watch crystal to minimize reflections and improve visibility.

Antimagnetic: A feature that protects the watch movement from the negative effects of magnetic fields.

Automatic Winding: A mechanism that automatically winds the watch's mainspring through the natural motion of the wearer's wrist.

Balance Wheel: A weighted wheel in a watch that oscillates back and forth to regulate the movement's timing.

Balance Spring: A thin strip of metal that is coiled and attached to the balance wheel, providing the restoring force for its oscillations.

Barrel: The cylindrical container in a watch that houses the mainspring, which stores and releases energy to power the movement.

Bezel: The ring surrounding the dial of a watch that can be stationary or rotate to perform various functions, such as measuring elapsed time or calculating additional time zones.

Bridge: A supportive plate or structure that holds various parts of the watch movement in place.

Bracelet: A metal band or strap attached to a watch case that is worn around the wrist.

Breguet Hands: A style of watch hands characterized by their hollowed-out, pomme-shaped tips.

Buckle: A small device used to fasten the watch strap or bracelet around the wrist.

Bumper Movement: A type of automatic movement that uses a rotor with springs to provide a cushioned winding action.

Cambered Crystal: A curved watch crystal that provides a unique aesthetic and improves visibility from different angles.

Caliber: The specific model or type of movement used in a watch.

Calendar: A complication that displays the date, day, month, and sometimes leap year information.

Canteen Crown: A screw-down crown with a protective cover, commonly found on diver's watches for enhanced water resistance.

Carat: A unit of measurement used to denote the weight of gemstones, with one carat equal to 200 milligrams.

Carrousel: A rotating platform that holds the regulating organ of a watch, similar to a tourbillon but with a different mechanism.

Case: The outer shell that protects the watch movement and holds the dial, hands, and crystal.

Caseback: The rear cover of the watch case that can be opened to access the movement or remain sealed for water resistance.

Ceramic: A hard and scratch-resistant material used in watch cases, bezels, and bracelets.

Champlevé: A decorative technique where recessed areas of a metal surface are filled with enamel or other materials.

Chapter Ring: A ring or scale located on the outer edge of the dial that displays minute or second markers.

Chasing: The process of engraving decorative patterns or designs on a watch case or movement.

Chime: A mechanism in a watch that produces audible sounds, such as alarm chimes or minute repeater tones.

Chronograph: A watch with a built-in stopwatch function that can measure elapsed time.

Chronometer: A highly accurate watch that has passed rigorous testing by an official organization, such as COSC.

Côtes de Genève: A decorative pattern of parallel lines often seen on the plates and bridges of high-end watch movements.

Crown: The small knob on the side of the watch case used for setting the time and date, as well as winding the watch.

Crystal: The transparent cover that protects the dial of the watch. It can be made of various materials, such as sapphire, mineral, or acrylic.

Cyclops: A magnifying lens typically placed on top of the date window to enhance readability.

Damaskeening: A decorative technique where intricate patterns are engraved on the surface of watch movements.

Date Window: A small window on the dial that displays the current date.

Day-Date: A watch that displays both the day of the week and the date.

Day-Night Indicator: A feature that indicates whether it is day or night, often represented by a rotating disc with a sun and moon.

Deployment Clasp: A type of watch buckle that unfolds to provide a secure and comfortable closure.

Dial: The face of the watch where the time and other functions are displayed.

Digital Display: A type of watch display that uses numbers or symbols to indicate the time and other functions.

Diver's Watch: A watch specifically designed for underwater use, typically with enhanced water resistance and features such as a unidirectional rotating bezel and luminescent markers.

Dual Time Zone: A feature that allows the watch to display the time in two different time zones simultaneously.

Ebauche: The base movement produced by a watch manufacturer, which is then modified and decorated to create a specific watch model.

Eccentric: A term used to describe the position or alignment of certain watch components that are intentionally off-center or not in the middle.

Electromechanical: A type of watch movement that combines electronic components with mechanical elements.

Escapement: The mechanism in a watch that controls the release of energy to the balance wheel, regulating the timekeeping.

Exhibition Caseback: A transparent caseback that allows the wearer to view the movement of the watch.

Face: The front side of a watch, typically referring to the dial.

Flyback Chronograph: A chronograph function that allows the user to reset and restart the stopwatch with a single push of a button.

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

Fusee: A conical-shaped device used in mechanical watches to provide constant force to the movement as the mainspring unwinds.

Galvanic Dial: A dial that has been chemically treated or electroplated to achieve a specific color or finish.

Geneva Seal: A certification mark awarded to watches produced in the canton of Geneva, Switzerland, indicating high-quality craftsmanship and finishing.

GMT: Abbreviation for Greenwich Mean Time, which represents the standard time at the Prime Meridian.

Grande Sonnerie: A complex chiming mechanism in a watch that strikes the hours and quarters automatically.

Guilloché: A decorative technique where intricate patterns are engraved on the surface of watch dials or cases.

Hacking: A feature that stops the movement of the second hand when the crown is pulled out, allowing for precise time setting.

Hairspring: A thin, coiled spring that oscillates with the balance wheel to regulate the timekeeping of a watch.

Hand-winding: A watch movement that requires manual winding by turning the crown to power the mainspring.

Horology: The study and science of timekeeping and the art of making timepieces.

Hour Hand: The hand on a watch that indicates the current hour on the dial.

Hybrid Movement: A watch movement that combines both mechanical and electronic components.

Indices: The hour markers on a watch dial.

In-house Movement: A watch movement that is designed, developed, and produced by the same watch brand.

Incabloc: A shock protection system used in mechanical watches to protect delicate components from damage caused by impact or vibration.

Interchangeable Straps: Watch straps or bracelets that can be easily swapped or changed to customize the look of the watch.

Jewels: Small synthetic or natural gemstones used as bearings in the movement to reduce friction and enhance durability.

Jumping Hour: A complication that displays the hour in a separate aperture or window, changing instantaneously at the top of each hour.

Jumbo: Refers to a larger-sized watch case or dial, often exceeding the standard dimensions.

Jubilee Bracelet: A type of watch bracelet characterized by its five-piece link design, known for its flexibility and comfort.

Jumping Seconds: A complication that displays the seconds in discrete, or "jumping," increments rather than a smooth continuous sweep.

Jewel Setting: The process of securing gemstones onto the watch case, dial, or bezel using prongs or other mountings.

Julian Date: A system that assigns a unique number to each day of the year, used in some watches to indicate the date.

JLC: Abbreviation for Jaeger-LeCoultre, a renowned Swiss watch manufacturer.

Jump Hour: A complication that displays the hour on a rotating disc or digital display, changing instantly at the top of each hour.

Jour: The French word for "day," often used in watchmaking to indicate a day-date complication.

Jewel Hole: A small, precisely machined hole in the watch movement where a jewel bearing is placed to reduce friction.

Jubilee: A celebration or commemorative edition of a watch model, often marked by special design elements or limited production.

Jeweled Escapement: An escapement mechanism in a watch movement that incorporates synthetic or natural gemstone bearings for reduced friction.

Key-Wind Watch: A type of watch that requires a special winding key to wind the mainspring.

Keyless Works: The mechanism in a watch that allows for winding and setting the time without the use of a winding key.

Kinetic Watch: A type of watch that uses the motion of the wearer's arm to generate and store energy, which powers the watch.

Kish: A type of abrasive powder used in polishing and finishing watch components.

Kronometer: A term used to describe a watch that has been certified as highly accurate by an official observatory.

Luminous: Refers to watch hands, hour markers, or dials that are coated with a substance that emits light in the dark, typically using a phosphorescent material.

Lume: Short for luminescent, it refers to the luminous material used on watch hands, hour markers, or dials.

Lunar Phase: A complication on a watch that displays the current phase of the moon, usually through a rotating disk or subdial.

Lépine: A type of pocket watch or movement design characterized by the crown and winding mechanism being located at the 12 o'clock position rather than on the side.

Limited Edition: A watch produced in a restricted quantity, often with a specific number assigned to each piece, making it more exclusive and collectible.

Long Power Reserve: A watch that can run for an extended period without requiring winding or additional power.

Luxury Watch: A high-end timepiece typically crafted with exquisite materials, exceptional craftsmanship, and often associated with prestigious brands.

Manual-Winding: A watch that requires manual winding by turning the crown to wind the mainspring and power the movement.

Mechanical Watch: A watch that operates using a mechanical movement, typically powered by a mainspring and regulated by a balance wheel.

Micro-rotor: A miniature automatic winding system in a watch that uses a small oscillating weight to wind the mainspring.

Minute Repeater: A highly complicated watch that can audibly chime the hours, quarter hours, and minutes on demand, usually through a series of hammers and gongs.

Moon Phase: A watch complication that displays the current phase of the moon as it appears in the sky.

Movement: The inner mechanism of a watch that powers its timekeeping functions. It includes components such as the mainspring, balance wheel, escapement, and gears.

Mainspring: A coiled spring in a watch that stores energy when wound and gradually releases it to power the movement.

Magnetism: The presence of magnetic fields that can affect the accuracy of a mechanical watch. Anti-magnetic watches are designed to resist these magnetic forces.

Mineral Crystal: A type of watch crystal made from hardened mineral glass that offers good scratch resistance.

Multi-Time Zone: A watch that displays the time in multiple time zones simultaneously, often through the use of additional subdials or rotating discs.

NATO Strap: A type of nylon strap originally developed for military use, characterized by its durable and adjustable design with multiple loops.

Numerals: The symbols or characters used on a watch dial to indicate the hours, typically in Arabic or Roman numerals.

Nacre: Also known as mother-of-pearl, it is a material often used on watch dials, known for its iridescent appearance.

Non-Magnetic: Refers to watches or watch components that are not affected by magnetic fields and can maintain their accuracy even when exposed to magnetic forces.

Normal Time: Also known as standard time, it refers to the conventional 12-hour time system used in everyday life.

Nut: A small threaded fastening device used in watchmaking to secure various components, such as the crown or screws.

Observatory Chronometer: A watch that has undergone precision tests and received a certification from an official observatory for its accuracy.

Oechslin, Ludwig: A renowned watchmaker and horologist known for his innovative watch designs and contributions to the industry.

Open-Heart: A watch design that features a cutout or aperture on the dial, revealing the movement's balance wheel or other internal components.

Oscillation: The back-and-forth motion of the balance wheel in a mechanical watch, which regulates the timekeeping function.

Overcoil: A special curved shape given to the hairspring in a watch movement to improve its isochronism and accuracy.

Oyster Case: A type of watch case design introduced by Rolex, known for its water resistance and screw-down crown.

Perpetual Calendar: A highly complex watch complication that displays the date, day of the week, month, and leap year cycle, automatically adjusting for months of different lengths and leap years.

Power Reserve: The amount of time a mechanical watch can run without being wound, typically indicated by a subdial or hand on the watch dial.

PVD (Physical Vapor Deposition): A coating process used to create a thin, durable layer on watch cases or components, providing enhanced protection and different color options.

Pulsation Scale: A scale often found on chronograph watches that allows for measuring a patient's pulse rate.

Pusher: A button on a chronograph watch used to start, stop, and reset the timing functions.

Quartz Movement: A type of movement in a watch that relies on a quartz crystal to regulate timekeeping, known for its accuracy and battery-powered operation.

Quickset Date: A feature in a watch that allows for rapid adjustment of the date display, typically achieved by pulling the crown out to a specific position and turning it.

Quick Release: A mechanism or system that allows for easy and quick removal or attachment of watch straps or bracelets without the need for tools.

Rattrapante (or Split-Seconds): A type of chronograph complication that features an additional central hand, allowing for the measurement of intermediate or multiple time intervals.

Rehaut: The inner edge or flange of a watch dial that surrounds the dial itself, often featuring hour markers or other additional markings.

Regulator: A type of time display where the hour, minute, and second hands are positioned on separate subdials or axes, providing improved legibility.

Reserve de Marche: A power reserve indicator that shows the remaining running time of a mechanical watch before it needs to be wound again.

Retrograde: A type of complication where a hand moves along an arc and then jumps back to its starting position instead of making a complete revolution.

Rotating Bezel: A bezel on a watch that can be turned, typically used for timing purposes, such as measuring elapsed time or tracking additional time zones.

Sapphire Crystal: A highly durable and scratch-resistant watch crystal made of synthetic sapphire, known for its clarity and resistance to damage.

Screw-Down Crown: A crown on a watch that can be screwed tightly into the case to enhance water resistance.

Skeleton Watch: A watch with a transparent dial and case that showcases the movement's intricate inner workings.

Subdial: A smaller dial within the main dial of a watch, often used to display additional complications such as a second time zone, date, or chronograph functions.

Sunburst Dial: A dial with a textured finish that features radiating lines, creating a shimmering effect reminiscent of sunlight.

Super-LumiNova: A popular luminescent material used on watch hands, hour markers, and dials to enhance visibility in low-light conditions.

Sweep Second Hand: The long, central hand on a watch that indicates seconds, moving smoothly and continuously instead of ticking.

Tachymeter: A scale on a watch bezel or dial that allows for measuring speed based on time and distance calculations.

Tourbillon: A highly complex and visually captivating complication in a watch that counters the effects of gravity on the movement by placing the escapement in a rotating cage.

Titanium: A lightweight and durable metal often used in watch cases and bracelets due to its excellent strength-to-weight ratio and resistance to corrosion.

Tonneau: A watch case shape characterized by its barrel-like design with curved sides and often rounded ends.

Totalizer: A subdial or additional mechanism on a watch that displays cumulative elapsed time for functions such as chronograph or dual time zone.

Tritium: A radioactive material previously used in watch luminescent dials, now largely replaced by non-radioactive alternatives like Super-LumiNova.

Twelve-Hour Format: A time display system based on a 12-hour cycle, commonly used in everyday life as opposed to the 24-hour format.

UTC (Coordinated Universal Time): The primary time standard used worldwide, often referred to as Greenwich Mean Time (GMT), serving as a reference for timekeeping across different time zones.

Ultra-Thin: Describes a watch or movement that is exceptionally thin, often achieved through innovative design and the use of slim components.

Unidirectional Bezel: A bezel on a dive watch that rotates in one direction only, typically counterclockwise, to measure elapsed time underwater and prevent accidental rotation.

Universal Time: A feature or complication in a watch that allows for the simultaneous display of the current time in multiple time zones.

Urushi: A traditional Japanese lacquer technique often used in high-end watch dials, known for its rich, glossy finish and intricate craftsmanship.

Vibrations per Hour (VPH): A measurement used to indicate the frequency at which the balance wheel oscillates in a mechanical watch. It is often expressed in terms of beats per hour.

Valjoux: A renowned Swiss movement manufacturer known for producing high-quality chronograph movements used by various watch brands.

Vandalsim: The act of intentionally damaging or defacing a watch or its components.

Vibration: The oscillation or back-and-forth motion of the balance wheel in a mechanical watch, typically measured in vibrations per hour (VPH).

Vintage: Refers to watches that are at least 20-30 years old, often sought after for their historical value, design, and collectability.

Visual Complications: Additional features on a watch's dial or display that provide aesthetic enhancements, such as a moon phase or power reserve indicator.

Water Resistance: The ability of a watch to withstand exposure to water to a certain depth without water entering the case.

Winding: The act of manually or automatically providing energy to a watch's mainspring to power the movement.

Winding Crown: The knob on the side of a watch case used for winding the mainspring and setting the time.

World Time: A watch complication that allows for the simultaneous display of the time in multiple time zones around the world.

Wristwatch: A watch designed to be worn on the wrist, typically with a strap or bracelet.

X-Factor: A term used to describe the intangible quality or unique appeal of a watch that sets it apart from others, often subjective and difficult to define.

Yellow Gold: A type of gold commonly used in watch cases and bracelets, known for its warm and rich yellow color.

Zenith: A prestigious Swiss watch manufacturer known for producing high-quality mechanical movements and timepieces.

Zone Time: The local time in a specific geographic region or time zone.