If you’re new to watches, there are likely a lot of terms and phrases you hear that you don’t understand. I’m not new to watches, and I’m still constantly googling things I hear or read on watch blogs. To make things a little easier, here is a list of jargon with some simple definitions to help. This is by no means a complete list. I could and may do additional posts on this topic. These are just some terms I remember learning when I first got into watches.
Bezel: A bezel is a surround on the face of the watch that holds the watch crystal in place. A lot of sport watches use the bezel to add additional functionality. For example, a dive watch bezel rotates and has numbers painted or engraved on it allowing it to act as a timer.
Chronograph: Chronograph is a watch complication that allows you to start, stop, and reset a timing hand similar to a stopwatch.
Chronometer: This is a watch that has been tested and certified to meet certain accuracy standards in various environments. For example, a Contrôle Officiel Suisse des Chronomètres (COSC) certified watch meets all the standards set by that organization.
Complication: A complication is anything a mechanical watch does besides tell time. For example showing the date, day of the week, or having a chronograph function.
Crown: The crown of a watch is the knob usually located on the right side of the watch case that either screws out or can be simply pulled out to wind and or set the watch.
Finishing: Finishing as it sounds, is the finishing work done on watch components. These are mostly aesthetic decorations on metal components of the watch, whether that’s polishing, beveling, adding grain to the metal, et cetera. There are many techniques and styles with regards to finishing, some hand-done some by machine. Very intricate hand-done finishing can add significant value to a watch. Some of the best examples of this can be found on A.Lange & Sohne and Patek Phillipe watches.
GMT: GMT stands for Greenwich Mean Time. This is the mean time at the Royal Observatory in Greenwich, London. The time standard was used when traveling across the world when constantly passing through other time zones. Because of this, it became the name given by Rolex to its famous pilot watch that could simultaneously tell the time in different time zones. Now a GMT watch is one with a complication that allows for viewing of multiple time zones at once.
Mainplate & Bridge: The bridge connects to the mainplate and together they make the foundation of a watch movement to which all other pieces attach.
Movement: This is the engine of the watch, it powers all of the functions of the timepiece. This can also be referred to as a caliber, but usually, a caliber is referencing a specific movement. For example, the Omega caliber 321 is the specific chronograph movement that was in the watch that went to the Moon.
Repeater: A repeater is a complication that chimes to tell you the time on demand. Usually, with a very pleasant ping sound, the watch will ding the number of times that match what time it is. A minute repeater does this to the minute.
Tourbillon: A tourbillon is a mechanism that houses the escapement and balance wheel in a rotating cage, in an attempt to balance out any negative affects gravity can have on the timepiece when it is stuck in a certain position for a long time. It does this by continuously rotating the entire balance wheel/escapement assembly. This is more useful in clocks that are stationary than a watch which is usually in motion on the wearer’s arm but is still technically interesting and just nice to look at.