The meaning of KEY is a usually metal instrument that is used to open a lock or to start or access a mechanism. How to use key in a sentence.

Each key has its own scale, beginning and ending on the note that defines the octave of the next scale. The key of C-major uses a scale that starts on C and uses only the white keys of the piano.

KEY definition: 1. a piece of metal that has been cut into a special shape and is used for opening or closing a…. Learn more.

Definition of key noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

Of crucial importance; significant: key decisions; the key element of the thesis.

The usual type of key is a small metal object that you insert into a narrow opening and turn.

A key is a specially shaped piece of metal that you place in a lock and turn in order to open or lock a door, or to start or stop the engine of a vehicle.

Key definition: A determining factor in accomplishing or achieving something.

any of various devices resembling or functioning as a key: The key of an old-fashioned clock is used to wind it up. something that provides a means to achieve, become skilled at, or …

A key is a piece of metal that fits inside a lock and turns to open it. You might have a key ring with a house key, a car key, and maybe several more keys.