1.-key: instrument used to tighten or loosen nuts.
2.-KEY; Portable fire weapons, mechanism used to shoot them.
3.-key: wedge that secures the union of two pieces of wood or iron, wedged between them.
4.-key: instrument used by dentists to start grinding wheels.
5.-KEY; In logic, mathematics and other disciplines, sign grouping several elements of a series.
6.-key: in certain kinds of struggle, lance which consists in making prey in the body of the opponent, or any part of it, to immobilize him or knock him down.
7.-key: subject whose prior approval is required to be able to examine others.
8.-key: in music, key, the staff.