The watch glossary
The words used in lot descriptions and sale rooms, defined in one or two sentences each.
A
- Aftermarket
- A part not made by the original brand, such as a diamond bezel or replacement dial. It lowers collector value.
- Automatic
- A mechanical movement wound by a rotor that turns as the wrist moves.
B
- Bezel
- The ring around the crystal. It may be fixed or rotate to time dives or track a second time zone.
C
- Calibre
- The movement model inside a watch, identified by the maker’s number.
- Case back
- The rear cover of the case. It may be solid, engraved or display the movement through sapphire.
- Chronograph
- A watch with a stopwatch function, started and stopped by pushers on the case.
- Chronometer
- A watch whose movement has passed independent precision testing, such as COSC certification.
- Complication
- Any function beyond hours, minutes and seconds, such as a date, chronograph or moon phase.
- Crown
- The knurled button used to wind the watch and set the time. A screw-down crown seals against water.
D
- Dial
- The face of the watch, carrying the indices, hands and printed text.
F
- Full set
- A watch offered with its original box, papers and accessories.
G
- GMT
- A complication showing a second time zone, read from a 24-hour hand and, on most models, a 24-hour bezel.
H
- Hammer price
- The winning bid when a lot closes, before the buyer’s premium is added.
I
- Increment
- The minimum amount by which a new bid must exceed the current bid.
J
- Jewels
- Synthetic rubies used as low-friction bearings in a mechanical movement.
L
- Lot
- A single item, or group of items, offered for sale as one unit.
- Lugs
- The projections on the case that hold the strap or bracelet.
M
- Manual wind
- A mechanical movement wound by turning the crown by hand.
- Movement
- The mechanism that measures and displays time.
N
- No reserve
- A lot that sells to the highest bidder regardless of price.
P
- Papers
- The original warranty card or certificate linking a serial number to its first sale.
- Polished
- A case that has been refinished. Heavy polishing softens edges and can reduce value.
- Power reserve
- How long a fully wound mechanical watch runs before stopping.
- Provenance
- The documented history of a watch’s ownership.
- Proxy bid
- A maximum bid entered in advance. The system bids for you in increments up to that amount.
Q
- Quartz
- A battery-powered movement regulated by a vibrating quartz crystal.
R
- Reference number
- The manufacturer’s code for a model and its configuration.
- Rehaut
- The inner flange between dial and crystal, sometimes engraved with the serial number.
- Reserve
- A confidential minimum price below which a lot will not sell.
S
- Serial number
- The unique number identifying an individual watch and its production period.
- Service history
- The record of maintenance carried out on a watch.
- Soft close
- A rule that extends a lot’s closing time when a bid arrives in the final minutes.
T
- Tourbillon
- A rotating cage that carries the escapement, designed to average out positional errors.
U
- Unworn
- A watch that has never been worn, ideally still with its protective stickers.
W
- Water resistance
- The pressure a case is tested to withstand, expressed in metres or bar. It is not a diving depth.