: a small device that is used to open a lock or start an automobile
b
: a device having the form or function of a key
a key for winding a clock
2
: a means of gaining or preventing entrance, possession, or control
3
a
: something that provides an explanation, solution, or means of identifying
the key to a riddle
b
: a series of phrases or statements that describe characteristics by which plants or animals of a particular group differ and are used to aid in identification
c
: a map legend
4
: one of the levers with a flat surface that is pressed by a finger in operating a machine or playing an instrument
5
: a system of seven musical tones arranged in relation to a keynote from which the system is named
the key of C
6
: a characteristic style or tone
7
: a small switch for opening or closing an electric circuit
key
2 of 4verb
keyed; keying
1
: to adjust the musical pitch of
2
: to bring into harmony
3
: to make nervous, tense, or excited—usually used with up
all keyed up about the test
4
: to record by operating the keys of a machine
key each price into the cash register
key
3 of 4adjective
: of great importance
the key people in the organization
the key question is "Can we afford it?"
use key words in an outline
key
4 of 4noun
: a low island or reef
the Florida Keys
Etymology
Old English cǣg "key"
from Spanish cayo "a low island or reef"
Legal Definition
key
adjective
: of vital importance (as in a business organization) especially so as to be specially insured to the benefit of an employer
key man
key employee insurance
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