A cock is an adult male chicken.

You refer to a male bird, especially a male game bird, as a cock when you want to distinguish it from a female bird.

A man's cock is his penis.

If you cock a part of your body in a particular direction, you lift it or point it in that direction.

If someone cocks their ear, they try very hard to hear something from a particular direction.

When someone cocks a gun, they set a small device in the gun so that it is ready to fire.