Definition of key
1 a
:a usually metal instrument by which the bolt of a lock is turned
b
:any of various devices having the form or function of such a key
- a key for winding a clock
2 a
:a means of gaining or preventing entrance, possession, or control
b
:an instrumental or deciding factor
- the key to her success
3 a
:something that gives an explanation or identification or provides a solution
- the key to a riddle
b
:a list of words or phrases giving an explanation of symbols or abbreviations
- a pronunciation key in a dictionary
c
:an aid to interpretation or identification :clue
- a key to understanding their motivation
e
:a map legend
4 a
:a part to be depressed by a finger that serves as one unit of a keyboard;
also
:a representation of such a key (such as a space delineated on a touch screen)
- Tiny keys on your iPhone's screen can be difficult to hit accurately.
- —Cherlynn Low
b
:one of the levers of a keyboard musical instrument that actuates the mechanism and produces the tones
c
:a lever that controls a vent in the side of a woodwind instrument or a valve in a brass instrument
5
:a system of tones and harmonies generated from a hierarchical scale of seven tones based on a tonic
- the key of G major
6 a
:characteristic style or tone
b
:the tone or pitch of a voice
c
:the predominant tone of a photograph with respect to its lightness or darkness
7
:a decoration or charm resembling a key
8
:a small switch for opening or closing an electric circuit
- a telegraph key
9
:the set of instructions governing the encipherment and decipherment of messages
- an encryption key
10
:a free-throw area in basketball :free throw lane
- a jump shot from the top of the key
11 a (1)
:cotter pin
(2)
:cotter
b
:a keystone in an arch
c
:a small piece of wood or metal used as a wedge or for preventing motion between parts
12
:samara
