Watch Glossary: Essential Terms Every Collector Should Know

From “chronograph” to “tourbillon,” understanding watch terminology is key to making informed decisions—whether you’re buying your first timepiece or building a serious collection. This comprehensive watch glossary from The 1916 Company defines the most important horological terms in clear, collector-friendly language. Whether you’re exploring pre-owned icons or technical innovations, use this guide to navigate the world of luxury watches with confidence. 

Core Watch Anatomy & Movement

Automatic-Winding Movement (Self-Winding)

A mechanical movement that self-winds via a rotor as you wear it—no daily winding needed. While ideal for daily wear, these watches can benefit from occasional manual winding. (~30–40 turns) to extend power reserve. 

Balance Spring (Hairspring)

A fine spiral spring that regulates oscillation, helping control timing. Learn more about how De Bethune reimagines the balance spring with a flat, self-centering design. 

Balance Wheel

Oscillates to divide time into equal segments—the beating heart of a mechanical movement. 

Barrel

A drum housing the mainspring; size affects power reserve. 

Breguet Overcoil

A hairspring with an upturned outer curve that improves isochronism and timekeeping accuracy. 

Bridge

A fixed frame inside the movement that supports gears and components. 

Calibre (Caliber)

Refers to the movement inside a watch; can indicate the manufacturer or technical lineage. 

Complication

Any feature beyond basic timekeeping (e.g., chronograph, date, GMT, moonphase). 

Escapement

The mechanism that regulates energy release from the mainspring to the balance wheel in timed pulses. 

Gear Train

The series of gears that transmits power from the mainspring to the escapement—essential for turning the hands and powering complications. 

Hand-Wound (Manual Movement)

A mechanical movement requiring manual winding via the crown. Preferred by purists for its direct connection with the watch’s power source. 

Hairspring

See Balance Spring. Learn more about how H. Moser et Cie. redeveloped cylindrical hairsprings with a modern twist. 

Incabloc / Shock Protection

A shock-absorbing system designed to protect a watch’s delicate balance wheel pivots from damage due to impact. Developed in Switzerland, Incabloc is one of the most widely used anti-shock mechanisms in both vintage and modern mechanical watches—valued for preserving movement longevity and precision. 

Jewels

Synthetic rubies placed at key pivot points within a watch movement to reduce friction and wear between moving parts. Jewels help ensure smoother operation, greater accuracy, and longer lifespan of mechanical components. Most modern watches use synthetic (not natural) jewels—common counts range from 17 to over 30 depending on complications. 

Movement Holder / Movement Ring

A structural component that keeps the movement securely in place within the case. Typically found between the movement and the inner wall of the case, this ring ensures stability and proper alignment—particularly important during servicing or assembly. 

Rotor

A semi-circular, weighted piece that swings with wrist movement to wind an automatic movement. 

Case & Construction 

Case

The housing that protects the movement—available in steel, gold, titanium, and other materials. 

Exhibition Case Back

A transparent caseback (usually sapphire) that reveals the watch’s movement—popular for showcasing automatic or decorated calibers. 

EOL (End of Life)

A battery indicator feature on quartz watches—ticks every 4 seconds to signal battery replacement is needed. 

Gold Plating

 A thin layer of gold applied to a watch case or bracelet through electroplating. The thickness is measured in microns, and common markings include “GP,” “HGE,” or “GE.” Stamps with fractions (e.g., 1/20) indicate the proportion of gold content relative to the base material. While visually similar to solid gold, gold-plated components can wear over time with regular use. 

Guilloché

A decorative engraving technique that creates intricate, repeating patterns—often on dials, rotors, or casebacks. Traditionally done by hand using a rose engine lathe, guilloché adds visual depth and texture, reflecting light in elegant ways. Some brands, like Breguet, are renowned for their mastery of this artisanal detail. 

Hacking Seconds

Also known as “stop seconds,” this feature stops the seconds hand when the crown is pulled out, enabling precise time synchronization. 

Lug

The protrusions on a watch case where the strap or bracelet is attached. Lug width and shape influence how the watch wears on the wrist. 

Pusher

A button on the watch case used to operate complications such as a chronograph, calendar, or GMT reset. Often positioned at 2 and 4 o’clock on chronograph watches. 

Screw-Down Crown

A crown that threads into the case to create a water-tight seal, increasing water resistance and preventing accidental adjustments. Common on dive and sports watches. 

Skeleton Watch

A design that exposes the movement by removing sections of the dial or bridges, highlighting the watch’s mechanical beauty. Read more about the subtle differences in skeleton watches here. 

Uni-directional Bezel

A rotating bezel that only turns counter-clockwise—typically used in diving watches to safely track elapsed time. Learn more about the features and explore pre–owned dive watches. 

Timekeeping Complications & Functions

Alarm

An additional function on a watch that triggers a sound or vibration at a preset time—great for reminders without your phone. 

Altimeter

Displays altitude above sea level for outdoor activities and aviation. 

AM/PM Indicator (Day-Night Indicator)

Displays whether it’s before or after midday—helpful when setting dual-time or world-time functions. 

Annual Calendar

A complication that correctly adjusts for all month lengths—except February in leap years. 

Calendar

Displays day, date, and sometimes month/year—simple yet useful. 

Chronograph

A wristwatch with a built-in stopwatch function—typically with a central seconds hand and sub-dials measuring minutes/hours. Ideal for timing races or workouts, and often paired with tachymeter scales. See also: Flyback Chronograph, Rattrapante. 

Countdown Timer

Shows how much time remains from a preset interval—often with an alarm or auto-repeat. 

Diving Watch

A water-resistant timepiece (generally ≥200 m) with features like a unidirectional bezel and luminescent dial indices and hands—designed for underwater use. 

Dual Time (GMT)

Displays both local time and a second time zone—popular among frequent travelers. 

Equation of Time

A rare complication that displays the difference between mean solar time (standard time) and true solar time, accounting for Earth’s elliptical orbit. 

Flyback Chronograph

A chronograph that can be reset and restarted with a single push of a button—used in aviation and motorsports for quick sequential timing. 

GMT (Greenwich Mean Time)

A function that tracks multiple time zones—often with a 24-hour hand and rotating bezel. GMT watches from Grand Seiko demonstrate precise craftsmanship and beautiful finishing. Explore our curated selection of pre-owned GMT watches designed for the discerning traveler. 

Grand Sonnerie

A high complication that automatically chimes both the hours and the quarter hours, typically using a mechanical repeater mechanism. Unlike a minute repeater (which chimes only on demand), a grand sonnerie strikes the time at regular intervals and may also offer a silent mode. One of the most complex and prestigious complications in horology. 

Minute Repeater

A highly complex complication that chimes the time on demand using gongs and hammers. Considered one of the pinnacles of mechanical watchmaking. 

Moonphase

Displays the current phase of the moon through a rotating disk—typically a 29.5-day cycle. Adds romantic, visual appeal to a timepiece. 

Perpetual Calendar

A high-end calendar complication that automatically adjusts for leap years and varying month lengths—requiring no manual correction until the year 2100. Patek Philippe’s perpetual calendars are widely regarded as exemplary in horology. 

Power Reserve

The amount of time a fully wound watch will run before stopping. Measured in hours (e.g., 42h, 70h), it indicates how long the movement stores energy without needing to be worn or wound. Panerai is known for offering models with extended power reserves, often over 72 hours.] 

Rattrapante (Split-Seconds Chronograph)

A sophisticated chronograph complication with two central seconds hands. One hand can be stopped to time intermediate events while the other keeps running, then “catches up” when released. Ideal for timing laps or multiple events simultaneously. 

Slide Rule (Navigation Bezel)

A logarithmic scale on the bezel or dial used for calculations like fuel, speed, distance, or conversion—common on pilot chronographs. 

Sonnerie

A chiming complication that automatically strikes the hours (and sometimes quarters) like a clock tower. A Grande Sonnerie includes both minute repeater and striking functions. 

Tachymeter

A scale inscribed on the bezel or dial that allows the wearer to measure speed over a known distance—most often found on chronograph watches. 

Tourbillon

A rotating cage for the balance and escapement that counteracts the effects of gravity on timekeeping. A hallmark of haute horology. Tourbillon watches represent a pinnacle of watchmaking innovation. 

Display, Style & Design Details

Analog/Digital (Ana-Digi)

A hybrid display showing time both via traditional hands and digital digits. 

Analogue

A classic display style using hands and a dial, as opposed to numeric readouts. 

Aperture

A small window on the dial that displays specific information, like date or moonphase. 

Index / Indices

Markers on the dial that show hours (and sometimes minutes/seconds)—can be printed, applied, or lumed, each with a distinct visual style. 

Luminescence (“Lume”)

Coating on dial indices and hands (often Super-LumiNova) that glows in the dark, providing readability in low-light environments. 

External Components

Bezel

The ring around the crystal—can rotate (uni/bi-directional) or be fixed (e.g. tachymeter). 

Bracelet

A strap made of metal links—can be adjusted by adding or removing pieces. 

Cambered Crystal

A domed or curved crystal that enhances legibility and vintage style. 

Crown

The knob used to set the time, wind the mainspring, or adjust date/day. Variants include screw-down crowns for added water resistance. 

Crystal

The transparent cover (sapphire, mineral, or acrylic) that protects the dial. 

Deployment Buckle

A folding clasp that allows a strap or bracelet to open and close securely, preserving the material and ensuring a snug fit. 

Dial

The “face” of the watch that displays the time with dial indices and hands, numerals, and hands. Can include sub-dials for complications like chronograph or power reserve.  

Quality & Authentication

Chronometer

A watch movement certified by COSC for accuracy (–4/+6 sec/day mechanical; ±0.2 sec/day quartz). This distinction is often misunderstood—chronometer ≠ chronograph. 

Gray Market

Refers to the sale of authentic luxury watches through unauthorized dealers. While the watches are genuine, they are not sold by brand-authorized retailers and often lack official manufacturer warranties or after-sales support. Buying from trusted, authorized sources ensures service, authenticity, and peace of mind. 

Swiss Made

A legally protected designation indicating that a watch meets strict standards set by Swiss law. To qualify, at least 60% of its production costs must be Swiss-based, the movement must be Swiss, and final inspection must occur in Switzerland. “Swiss Made” remains a globally recognized mark of quality, craftsmanship, and precision in watchmaking. 

Collecting and Culture

Horology

The art and science of measuring time—and everything that surrounds it. Horology encompasses watchmaking, clockmaking, and the study of timekeeping history and technology. For collectors and enthusiasts, it reflects a deep appreciation for mechanical mastery and design innovation. 

Provenance

The documented history of a watch’s ownership, servicing, and origin. Provenance can significantly impact a timepiece’s value and desirability—especially for vintage or limited-edition models. 

Limited Edition

A watch released in a restricted quantity, often numbered and accompanied by certificates of authenticity. Limited editions appeal to collectors for their rarity and storytelling. 

Boutique Edition

A model produced exclusively for a brand’s boutique(s) rather than authorized retailers. Often features unique design elements or engravings—highly sought after by collectors. 

Discontinued Model

A reference or collection that’s no longer produced by the manufacturer. Discontinued watches may increase in collectability and value, depending on rarity, demand, and brand significance. 

Box and Papers

Refers to the original packaging and documentation (manual, warranty card, certificate) that came with the watch. “Full set” examples often command a premium on the pre-owned market. 

Full Set

 Industry shorthand for a pre-owned watch that includes its original box, papers, and accessories. Collectors prize full sets for their completeness and resale value. 

New Old Stock (NOS)

A vintage or discontinued watch that has never been worn and retains original factory condition. NOS pieces are rare and highly collectible, especially with original tags or stickers. 

Collector’s Piece

A term used to describe a watch that holds exceptional value or significance due to design, provenance, brand, or technical achievement. May include limited editions, prototypes, or milestone models.