24 hour wheel wheel turning at a 24 hours pace and activating the electronic calendar and the alarms based on it.
8 day movement a particular type of watch movement that requires winding only once  week.
A/N converter device that transforms an analog entry signal into numerical time display.
A/N display indication of different types of data (day, month, etc.) in the form of letters carried by rotating discs and appearing through windows. It can also be given by LCD or LED letters.
adjustment changing a pendulum’s period by lengthening or shortening it.
adjustment screw screw fixed into the rim of the first rockers to change their course.
analog display time indication by a relative movement of a marker on a scale (usually hands and dial).
anti-magnetic metallic alloys used in the manufacturing certain parts of the watch’s mechanism such as the balance wheel and escape wheel in order to protect the watch from magnetic fields.
astronomical complication a feature displaying the moon phase or the calendar.
automatic winding a watch with a mechanical movement that is wound while the wearer moves the arm and does not need a winding stem
auxiliary winding mechanism that serves to maintain a timepiece on during the winding operation.
balance oscillating device whose role is to regulate the speed of a mechanical watch’s movement.
battery indicator a display indication referring to the status of battery power.
bezel a ring commonly made of gold, gold plate or stainless steel
caliber the shape and dimensions of a watch movement (mechanical or quartz), its origin and manufacturing brand.
carat unit measuring gold alloys. 24 carats refer to pure gold.
chronograph watch provided with a conventional time display, supplemented by an additional mechanism that can switched on and off.
click a beak equipped lever used to put the teeth of a wheel in motion and operating under the action of a spring.
complication any feature of a watch.
crown wheel the wheel of the watch’s winding mechanism with the role of driving the ratchet wheel.
crown wheel screws security devices used to seal waterproof watches.
dial the display of a watch indicating the hour, the date, the phase of the moon, etc.
display mechanical, electrical or electronic indication of hours, minutes and seconds in a. The display can be done either by hands moving over a dial (analogue) or by numbers appearing in a window (digital). These figures can be supplemented by alphabetical information (alphanumeric display) or any other sign.
escapement A mechanism inside a watch’s movement whose main role is to transfer power from the mainspring to the regulator.
flyback chronograph a complication watch, which allows the user to stop, reset and restart the chronograph function.
Geneva ribbing see Geneva waves
Geneva seal a quality guaranteeing stamp usually placed on the movement of watches manufactured in the canton of Geneva.
Geneva stripes see Geneva waves
Geneva waves decorative stripes usually placed on the watch’s plate, bridge or rotor.
grand complication a watch with complex movement and numerous technical features.
guilloché a decoration made by engraving that is commonly found on plates and dials.
mixed display time indication using hands to hours and minutes, and numbers for other functions.
sapphire crystal virtually scratchproof glass, with a hardness close to that of diamond.
stem a small device usually located on the side of the watch, used to set the pointers’ position or to turn the watch.
striking complication a possible to set feature like an alarm of a repeater.
timing complication a watch’s features referring to time measuring, like simple chronograph, counter chronograph, split-second flyback chronograph, independent second-hand chronograph, or jumping second-hand chronograph.
vermeil gold plating on the sterling silver.
waterproof often accompanied by the level of depth at which the watch can be immersed, this label indicates that the watch is sealed and can resist water pressure.