Alarm – a function on a watch that produces noise or a vibration when pre-set to a specific time
Altimeter – a function that measures how high you are above sea level
Analog display – a dial that displays the time through hour and minute hands
Annual calendar - a watch that shows the date, date and month. This complication automatically knows which months have 30 or 31 days, however the date will require resetting at the end of February since this only has 28 days.
Anti-magnetic – a watch not affected by magnetic fields that can be found in everyday items like TV’s, mobile phones and cars
Anti-reflective coating – a coating used on the glass of a watch to reduce the reflection and increase legibility
Aperture – a small window on the dial which often shows the date function
Arabic numerals – numbers on the dial in the form of 1,2,3 etc.
Automatic winding movement – a mechanical movement wound automatically by the motions of the wrist. Energy is created by the oscillating rotor which spins around as you and thus winds the mainspring which powers the watch
Balance spring – a component within a mechanical movement attached to the balance wheel that regulates the rate at which a balance wheel oscillates (also known as a hairspring)
Balance wheel – a component within a mechanical movement shaped like a weighted wheel that oscillates back and forth to regulate time equally
Barrel – an enclosed component within a mechanical movement that houses the mainspring. The barrel is responsible for the power reserve and so a double barrel increases the power reserve
Bezel – the outer rim that circles the glass of the watch. Some bezels rotate while others are fixed.
Bidirectional bezel – a bezel that rotates in both directions. Can be used to keep track of elapsed time
Calendar – a function that the date and month
Calibre – a term to identify the origin and maker of a movement
Cambered crystal – a type of glass which is arched to created a domed appearance
Case – the main body of a watch where the movement is housed
Case back – the back of a watch which lies against your wrist.
Chronograph - a watch equipped with timing functions that can be used just like that of a stopwatch
Chronometer - a watch that has been tested and certified to meet specific precision standards by an official testing institute. Any watch certified as a chronometer must have an accuracy of +6 and -4 seconds per day.
Column wheel – a rotating wheel in a chronograph used to operate various levers that start and stop the chronograph and return the hands to the zero position.
Complication – a function on a watch dial e.g date window, chronograph function, power reserve
COSC certified - COSC stands for the Controle Officiel Suisse des Chronometres or the Swiss Official Chronometer Testing Institute. This institute is responsible for certifying the official chronometer status of a watch. If a watch is COSC certified, then it must have an accuracy of +6 and -4 seconds per day.
Crown – a small knob on the side of the case most often used to change the time and date. Some mechanical watches can also be wound using the crown
Crystal – the clear glass used to protect the dial
Cyclops – a magnified lens used over some watch features like the date to make them appear larger
Date window – a small opening on the dial which shows the date
Day date – a feature on a watch which displays both the day and date either side by side or separately
Deployment buckle – a type of buckle on the strap which is expandable and lets you easily change the size of the strap
Dial – the face of the watch which displays the time and other features
Digital display – the time is shown through an electronic digital display rather than by hands
Diving watch – a timepiece with at least 200 metre water resistance, a unidirectional bezel and a screw-down crown and case back. All these functions allow the watch to remain protected from the damages of underwater diving.
DLC (Diamond Like Carbon) - a type of metal coating with a grey/black finish. DLC is similar to PVD coating but considered even more scratch and corrosion resistant
Domed crystal – the glass covering the dial is arched creating a domed effect
Dual time – a function that displays two time zones at once
EOL (End of Battery Life Indicator) – an indicator which tells you when the battery is low. Different manufacturers use different methods to indicate a low battery. One example is if a second hand usually sweeps, when the battery is low it will begin to tick.
Escapement – a component within a mechanical watch used to maintain the oscillations of the balance wheel. The escapement is one of the most important parts of any watch.
ETA movement – a movement made by ETA SA Manufacture Horlogère Suisse known as being one of the largest manufacturers of quartz and mechanical movements
Exhibition case back – the back of the watch protected by clear crystal so you can see the movement inside
Flyback chronograph – a type of chronograph that can be reset without having to stop the entire chronograph function. They are useful for people that want to record time quickly and consecutively like pilots or divers.
Folding clasp – a type of buckle of a strap that folds onto itself to secure
Frequency – the speed at which a watch ticks. The higher the frequency the more accurate the watch is thought to be
Gasket – a ring, often made from rubber, used to seal the case, crown and case back to prevent things like water and dust from getting inside
Gear Train - a system of gears that transfers the power from the mainspring to the escapement
Geneva stripes - a form of decoration and engraving found on the components of a watch’s movement
GMT (Greenwich Mean Time) function - a timepiece that displays more than one time zone on the dial
Gold plated - a thin layer of gold over another metal base such a silver or steel
Grand complication - one of the most complex achievements of haute horlogeries since it is a watch with a huge range of complicated functions. It is widely agreed that a watch has a grand complication if it has a minute repeater, moon phase, perpetual calendar, split-seconds chronograph and a grand and petite sonnerie.
Guilloche – an intricate pattern created by an engraving process
Hairspring – a component within a mechanical movement attached to the balance wheel that regulates the rate at which a balance wheel oscillates (also known as a balance spring)
Hand wound movement – a mechanical movement that must be wound manually by hand by turning the crown
Helium escape valve – a piece of technology found on some diving watches that allows helium atoms that have managed to creep into the case of a watch when diving below 200 metres to escape safely.
Hybrid smartwatch – a watch that uses still tells the time through classic hour and minute hands but is also equipped with smartwatch functions like text and call notifications and activity tracking
Incabloc Protection System – a system is used in most mechanical watches to help protect the critical alignment of components such as the hairspring and balance wheel in the event of an unexpected physical shock.
Indices – the markers found around the dial to point out every 5-minute interval
Jewels – the synthetic rubies and sapphires that are found in mechanical watches. They are used to reduce friction in the movement and the more jewels a movement has, the higher grade the watch is considered.
Lap timer – a chronograph function that allows you to measure broken time intervals or laps
Lever escapement - a component within a mechanical watch that connects the escape wheel and the balance wheel using two levers
Limited edition – a watch that is part of a limited series with only a set number of pieces being sold.
Lugs – the protruding parts of a watch that attach the case to the strap
Luminescence – a coating often found on the numerals and indices on the dial that allow these elements to glow in the dark
Mainplate – the base in which all the parts of a mechanical movement are attached
Mainspring – the source of power in mechanical watches. The mainspring must be wound before the watch can work
Manual winding movement – a mechanical movement that must be wound manually by hand by turning the crown
Mechanical watch – a watch not powered by a battery but my multiple components including a mainspring that must be wound. There are two types of mechanical watch: automatic winding and manual winding
Mineral glass – a type of watch glass made from heated hardened glass
Minute repeater – a function which displays the time with traditional hands but then chimes like a grandfather clock on demand. Minute Repeater watches are equipped with a button – often called a slider – which starts the mechanism to sound the time.
Mono-pusher chronograph – a watch with just one button at the side of the case which stops, starts and resets the chronograph functions.
Moonphase – a feature which displays the phase of the moon through an aperture on the dial as we would see it in the sky
Movement – the source of power to the watch
Perpetual calendar – a function which displays the day, date and month and accounting for the exact days in each month including leap years.
Pin buckle – a type of buckle on a strap that involves inserting a small pin through a hole to fasten and secure, just like that of a belt buckle.
Power reserve – the length of time a mechanical watch will run before it requires winding again
Pusher – the button on the side of the case to control chronograph function. Most chronographs have two pushers either side of the crown.
PVD (Physical Vapour Deposition) - a type of coating which combines ions and gas to create a thin layer of plating. PVD coating is extremely thin but it enables a colour to be applied to steel while also increasing its resistance to wear.
Quartz movement – a battery powered movement which works through the use of an electronic oscillator that transmits an electric current through a piece of crystal quartz.
Rattrapante – a chronograph watch equipped to time two intervals instead of only one, also known as a split seconds chronograph
Retrograde hand – a feature on the dial in the shape of a semi-circle. When the indicator comes to the end of the cycle, it moves backwards to the beginning.
Rotating bezel – a bezel that can rotate and isn’t fixed. There are two types or rotating bezels: bi-directional and uni-directional
Rotor – a component within a mechanical watch that swings back and forth when you move your wrist. The movement of the rotor winds the mainspring which then unwinds to power the watch
Sapphire crystal glass – a type of watch glass made from synthetically produced crystal and is known for being second only to diamond in its hardness
Screw down crown – a crown that screws in and out of the case to ensure water and dust cannot get into the movement
Second time zone indicator – a feature on a watch that shows more the time in two time zones at once
Self winding movement – a mechanical movement that winds itself as it is worn on the wrist. The movement you make allows the rotor inside to power the mainspring.
Shock absorber - a piece of technology used to protect the movement against shocks
Skeleton dial – a dial that has either small partial cuttings or the entire dial removed so you can see the mechanical movement beneath
Small seconds – a feature where the seconds is displayed through a separate sub-dial within the main dial
Smartwatch – a watch with certain technological and digital advantages that can be connected to a smartphone. A lot of smartwatches come with heart rate monitors, Wi-Fi capability and activity tracking.
Solar powered – a watch which sources its power from light which is stored and produced from solar panels beneath the dial.
Special edition – a watch which celebrates something special, often charity organisations or the anniversary of the manufacturer.
Split seconds chronograph - a chronograph watch equipped to time two intervals instead of only one
Spring bar – A steel pin which holds the strap into the lugs
Subsidiary dial – a smaller dial found within the main dial. Chrongraphs often have more than one sub dial to display different counters
Superluminova – the brand name of a luminescent substance often coated on the numerals and indices of a dial to make them glow in the dark
Sweeping seconds hand – a seconds hand that sweeps fluidly along the dial rather than in a ticking motion
Swiss made – a label given to watches that house a movement manufactured, cased and inspected by the manufacturer in Switzerland.
Tachymeter - a device usually found on the outer bezel of a watch to measure speed. A tachymeter is used in conjunction with a chronograph so the wearer can convert the elapsed time into an average speed.
Tang buckle - a type of buckle on a strap that involves inserting a small pin through a hole to fasten and secure, just like that of a belt buckle.
Tourbillon - an addition to the movement which involves mounting the escapement and balance wheel in a rotating cage to contradict any effects of gravity. This helps eliminate accuracy errors caused by gravity and other forces.
Unidirectional bezel – a type of bezel that can only be turned clockwise. These are often found on diving watches so the bezel cannot be accidentally rotated in the wrong direction and cause divers to miscalculate how much air supply they have left.
Water resistance – the unit used to identify how much pressure a watch can withstand under water
Worldtimer – a function which displays the time in 24 different time zone at once
