That depends, do you mean:
A male chicken, also called a rooster. This is the word's original meaning
In ornithologists' usage, the male of any bird
A type of tap, faucet or valve
Steamcock, a drain valve on a steam engine cylinder
Bibcock, a small type of valve
Sample ****, a small valve fitted in breweries and other process industries to check the product during manufacture
Stopcock, a valve used to restrict or isolate the flow of a liquid or gas through a pipe
Petcock, a small valve, primarily for draining liquid or releasing pressure from a vessel
Ballcock, a mechanism for filling water tanks
A part of a clock or watch used to support an outrigger bearing for a gear or lever
Balance ****, supports the balance wheel in a watch
Fly ****, supports the fly on a bracket clock
Back ****, supports the pendulum and pallet arbor
Cock, to prepare the hammer of a firearm for firing
Cockpit, the area in the front of a plane from which a pilot controls the aircraft
Shuttlecock, a high-drag projectile used in the sport of badminton
Cock, the NATO reporting name of the Antonov An-22
A Cocktail, a style of mixed drink
The pub
Or the surname?