key

noun (1)

\ ˈkē

Definition of key

(Entry 1 of 7)

1a : 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

2a : a means of gaining or preventing entrance, possession, or control

b : an instrumental or deciding factor the key to her success

3a : 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

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

4a : 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

6a : 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

11a(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

key

adjective

Definition of key (Entry 2 of 7)

: extremely or crucially important key issues a key moment in the game a key member of the staff

key

verb

keyed; keying; keys

Definition of key (Entry 3 of 7)

transitive verb

1 : to lock or secure with or as if with a key : fasten: such as

a : to secure (something, 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 key the strings

3 : to bring into harmony or conformity : make appropriate : attune remarks keyed to a situation

4 : to identify (a biological specimen) by a key (see key entry 1 sense 3d)

5 : to provide with identifying or explanatory cross-references instructions keyed to accompanying drawings— John Gartner

6 : to make nervous, tense, or excited —usually used with up was too keyed up to sleep

7 : to enter or input (text or data) by using a keyboard keying changes to a manuscript —often used with in or into key in a passwordinformation being keyed into a database

8 : to be essential to : play the most important part in defense keyed the victory

9 : to vandalize by scratching with a key someone keyed my car door

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 The middle linebacker was keying on the halfback.

3 : to operate a machine by means of a keyboard : keyboard

key

noun (2)

Definition of key (Entry 4 of 7)

: a low island or reef specifically : any of the coral islets off the southern coast of Florida the Florida Keys

key

noun (3)

Definition of key (Entry 5 of 7)

slang

: a kilogram especially of marijuana or heroin

Key

biographical name (1)

\ ˈkē

Definition of Key (Entry 6 of 7)

Francis Scott 1779–1843 American lawyer and author of "The Star-Spangled Banner"

Key

biographical name (2)

Definition of Key (Entry 7 of 7)

John (Phillip) 1961– prime minister of New Zealand (2008–16)

Other Words from key Synonyms & Antonyms More Example Sentences Learn More about key

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Examples of key in a Sentence

Adjective

He's a key player in the organization. The key question is “Can we afford it?”. Underline key words and phrases as you read. Their votes were key in getting the bill passed.

Verb

The changes to the manuscript are being keyed by the typist. her response was perfectly keyed to the situation

First Known Use of key

Noun (1)

before the 12th century, in the meaning defined at sense 1a

Adjective

1832, in the meaning defined above

Verb

14th century, in the meaning defined at transitive sense 1

Noun (2)

1693, in the meaning defined above

Noun (3)

1966, in the meaning defined above

History and Etymology for key

Noun (1), Adjective, and Verb

Middle English, from Old English cǣg; akin to Old Frisian kēi key

Noun (2)

Spanish cayo, from Taino

Noun (3)

by shortening & alteration from kilo

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Time Traveler for key

The first known use of key was before the 12th century

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More Definitions for key

key

adjective

English Language Learners Definition of key

(Entry 1 of 2)

: extremely important

key

verb

English Language Learners Definition of key (Entry 2 of 2)

: to enter (information) by using the keys of a computer, typewriter, etc.

US, informal : to have the most important part in (something)

See the full definition for key in the English Language Learners Dictionary

key

noun

\ ˈkē

Kids Definition of key

(Entry 1 of 4)

1 : an instrument by which the bolt of a lock (as on a door) is turned or by which an engine is started

2 : a device having the form or function of a key Can you wind the clock with the key?

3 : the thing that is necessary or most important in doing something To learn a skill, practice is the key.

4 : something (as a map legend) that gives an explanation : solution

5 : one of the levers with a flat surface that is pressed with a finger to activate a mechanism of a machine or instrument computer keys

6 : a system of seven musical tones arranged in relation to a keynote from which the system is named the key of C

key

verb

keyed; keying

Kids Definition of key (Entry 2 of 4)

1 : to regulate the musical pitch of

2 : to bring into harmony

3 : to record or enter by operating the keys of a machine The cashier keyed in the price.

key

adjective

Kids Definition of key (Entry 3 of 4)

: of great importance : most important She is one of our key players.

key

noun

Kids Definition of key (Entry 4 of 4)

: a low island or reef the Florida Keys

key

adjective

Legal Definition of key

: 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