Watch Glossary

A comprehensive guide to horological terminology. From basic watch components to complex complications.

A mechanical watch that winds itself using a rotor powered by the wearer's wrist movement. Also known as a self-winding watch.

A complication that automatically adjusts for months of different lengths, requiring manual correction only once a year (at the end of February).

The ring surrounding the crystal on the top of a watch case. Can be fixed, rotating, or bidirectional depending on the watch's function.

A metal plate that holds a watch movement component in place. Named for the component it supports.

The specific movement used in a watch. Usually identified by a reference number (e.g., Rolex Caliber 3235, Omega Co-Axial 8900).

A watch complication that functions as a stopwatch. Typically includes sub-dials for elapsed seconds, minutes, and sometimes hours.

Any function on a watch beyond simple timekeeping. Examples include date, chronograph, moon phase, perpetual calendar, and tourbillon.

The knob on the side of a watch case used to set the time and date. On water-resistant watches, it often screws down to ensure a seal.

A watch that combines multiple complex complications — typically a minute repeater, perpetual calendar, and chronograph — in a single timepiece.

A decorative engraving technique using intricate, repetitive patterns. Commonly seen on high-end watch dials.

The distance from the tip of one lug to the tip of the other, measured vertically. Determines how a watch sits on the wrist.

A coating applied to hands and indices to allow reading in dark conditions. Modern watches use Super-LumiNova or Chromalight.

A watch brand that designs and produces its own movements in-house, rather than sourcing them from external suppliers.

A complication that displays the current phase of the moon through an aperture on the dial.

A complication that automatically accounts for months of varying lengths and leap years, requiring no date adjustment for decades or centuries.

The length of time a fully wound mechanical watch can run before stopping. Displayed as hours (e.g., 70-hour power reserve).

A rotating cage that holds the balance wheel and escapement, designed to counteract the effects of gravity on timekeeping accuracy.

A radioactive isotope formerly used in luminous watch dials. Replaced by safer alternatives like Super-LumiNova since the late 1990s.