key

verb

keyed; keying; keys

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 password

information 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

Synonyms of key

• reconcile

Examples of key in a Sentence

The changes to the manuscript are being keyed by the typist.

her response was perfectly keyed to the situation

Recent Examples on the Web

Teams will likely be keying on Miami's passing game, which will also feature Heisman favorites at quarterback in Darrien Mensah and wide receiver Malachi Toney, leaving Fletcher to feast on what's left of the opposing defense. —Austin Perry Outkick, FOXNews.com, 3 June 2026

His metrics defending zone entries took a hit, and fans keyed in on puck management lapses. —Peter Baugh, New York Times, 2 June 2026

Home runs by Anaiyah Popoalii and Ashannalee Titialii keyed the win. —Eric Sondheimer, Los Angeles Times, 1 June 2026

If three weeks of product signals can be reviewed in minutes, why should key decisions still wait until next sprint? —Aleksejs Misarins, Forbes.com, 22 May 2026

Word History

Etymology

First Known Use

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

Phrases Containing key

• Allen key
• Alt key
• chroma-key
• church key
• Control key
• Delete key
• dichotomous key
• Escape key
• function key
• hold the master key
• hot key
• key card
• key chain
• key club
• key deer
• key fob
• key grip
• key light
• key lime
• key lime pie
• key ring
• key signature
• key to
• key word
• low-key
• master key
• off-key
• pound key
• public-key
• shift key
• skeleton key
• tab key
• under lock and key

Rhymes for key

• be
• bee
• bree
• cree
• fee
• flea
• flee
• free
• gee
• ghee
• glee
• he

Kids Definition

key

1 of 4 noun

ˈkē 

plural keys

1

a

: 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 4 verb

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 4 adjective

: 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 4 noun

: 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