I. ˈkē noun
Etymology: Middle English, from Old English cǣg; akin to Old Frisian kēi key
Date: before 12th century
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
2.
a. : a means of gaining or preventing entrance, possession, or control
b. : an instrumental or deciding factor
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
c. : an aid to interpretation or identification : clue
d. : an arrangement of the salient characters of a group of plants or animals or of taxa designed to facilitate identification
e. : a map legend
4.
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
5.
a. : one of the levers of a keyboard musical instrument that actuates the mechanism and produces the tones
b. : a lever that controls a vent in the side of a woodwind instrument or a valve in a brass instrument
c. : a part to be depressed by a finger that serves as one unit of a keyboard
6. : samara
7. : a system of tones and harmonies generated from a hierarchical scale of seven tones based on a tonic
the key of G major
8.
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
9. : a decoration or charm resembling a key
10. : a small switch for opening or closing an electric circuit
a telegraph key
11. : the set of instructions governing the encipherment and decipherment of messages
12. : a free-throw area in basketball
• keyed ˈkēd adjective
• key·less ˈkē-ləs adjective
II. verb
Date: 14th century
transitive verb
1. : to lock with or as if with a key : fasten : as
a. : to secure (as a pulley on a shaft) by a key
b. : to finish off (an arch) by inserting a keystone
2. : to regulate the musical pitch of
3. : to bring into harmony or conformity : make appropriate : attune
remarks key ed to a situation
4. : to identify (a biological specimen) by a key
5. : to provide with identifying or explanatory cross-references
instructions key ed to accompanying drawings — John Gartner
6. : to make nervous, tense, or excited — usually used with up
was key ed up over her impending operation
7. : keyboard — often used with in
8. : to be essential to : play the most important part in
defense key ed the victory
intransitive verb
1. : to use a key
2. : to observe the position or movement of an opposing player in football in order to anticipate the play — usually used with on
3. : keyboard
III. adjective
Date: 1913
: important , fundamental
key issues
IV. noun
Etymology: Spanish cayo, from Taino
Date: 1697
: a low island or reef ; specifically : any of the coral islets off the southern coast of Florida
V. noun
Etymology: by shortening & alteration from kilo
Date: 1968
slang : a kilogram especially of marijuana or heroin