a small metal instrument specially cut to fit into a lock and move its bolt.
any of various devices resembling or functioning as a key: the key of a clock.
something that affords a means of access: the key to happiness.
something that secures or controls entrance to a place: Gibraltar is the key to the Mediterranean.
something that affords a means of clarifying a problem.
a book, pamphlet, or other text containing the solutions or translations of material given elsewhere, as testing exercises.
a systematic explanation of abbreviations, symbols, etc., used in a dictionary, map, etc.: pronunciation key.: Compare legend (def. 4).
the system, method, pattern, etc., used to decode or decipher a cryptogram, as a code book, machine setting, or keyword.
one of a set of marked parts, designated areas, or levers pressed in operating a typewriter, computer terminal, calculator, etc.
a manually operated lever for opening and closing an electric circuit, used to produce signals in telegraphy.
(in a keyboard instrument) one of the levers that when depressed by the performer sets in motion the playing mechanism.
(on a woodwind instrument) a metal lever that opens and closes a vent.
the principal tonality of a composition: a symphony in the key of C minor.
the keynote or tonic of a scale.
tone or pitch, as of voice: to speak in a high key.
mood or characteristic style, as of expression or thought: He writes in a melancholy key.
degree of intensity, as of feeling or action.
a pin, bolt, wedge, or other piece inserted in a hole or space to lock or hold parts of a mechanism or structure together; a cotter.
a small piece of steel fitting into matching slots of a hub of a wheel or the like and the shaft on which the wheel is mounted so that torque is transmitted from one to the other.
a contrivance for grasping and turning a bolt, nut, etc.
Computers. a field or group of characters within a record that identifies the record, establishing its position among sorted records, and/or provides information about its contents.
(in a series of advertisements or announcements soliciting replies) a unique code inserted for each medium used, to determine the relative effectiveness of the media.
a device for opening and closing electrical contacts.
a hand-operated switching device ordinarily formed of concealed spring contacts with an exposed handle or push button, capable of switching one or more parts of a circuit.
Biology. a systematic tabular classification of the significant characteristics of the members of a group of organisms to facilitate identification and comparison.
Masonry. a keystone.
Architecture. (in a ribbed vault) a stone, as a boss, at the intersection of two or more ribs.
Masonry, Carpentry. a wedge, as for tightening a joint or splitting a stone or timber.
Carpentry. a small piece of wood set into a timber across the grain to prevent warping.
Building Trades. any grooving or roughness applied to a surface to improve its bond with another surface.
Basketball. keyhole (def. 2).
Photography. the dominant tonal value of a picture, a high-key picture having light tonal values and minimal contrast and a low-key picture being generally dark with minimal contrast.
Painting. the tonal value and intensity of a color or range of colors: Rembrandt's colors are characterized by their low key.
Botany. a samara.
Key, a member of the House of Keys.
keys, spiritual authority.
to regulate or adjust (actions, thoughts, speech, etc.) to a particular state or activity; bring into conformity: to key one's speech to the intellectual level of the audience.
Music. to regulate the key or pitch of.
to paint (a picture) in a given key.
to adjust the colors in (a painting) to a particular hue: He keyed the painting to brown.
to fasten, secure, or adjust with a key, wedge, or the like, as parts of a mechanism.
to provide with a key.
(in the layout of newspapers, magazines, etc.) to identify, through signs or symbols, the positions of illustrations or pieces of copy in a dummy.
to lock with or as if with a key.
Masonry. to provide (an arch or vault) with a keystone.
Computers. keyboard (def. 4).
to use a key.
Computers. keyboard (def. 4).
key in, Computers. keyboard (def. 4).
Football. to watch the position and movements of an opponent in order to anticipate a play: The defensive backs keyed on the star receiver.
Also key in on . to single out as of prime importance or interest; be intent on or obsessed with: a company that is keyed in on growth.
to bring to a particular degree of intensity of feeling, excitement, energy, nervousness, agitation, etc.: keyed up over the impending test.
to raise (a piece of masonry) by the insertion of a wedge or wedges.
to raise (the haunches of an arch) by the insertion of a voussoir.
Idioms about key
power of the keys, the authority of a pope in ecclesiastical matters, vested in him as successor of St. Peter.
Other definitions for key (2 of 4)
a reef or low island; cay.
Other definitions for key (3 of 4)
a kilogram of marijuana or other narcotic drug.
Other definitions for Key (4 of 4)
Francis Scott, 1780–1843, U.S. lawyer: author of The Star-Spangled Banner.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
How to use key in a sentence
Some former and current officials say they do not think ex-Washington officials will move many voters in key states.Former Pence aide says she will vote for Biden because of Trump’s ‘flat out disregard for human life’ during pandemic | Josh Dawsey | September 17, 2020 | Washington Post
The latest decision is another blow to the third-party ticket and a win for Democrats, who worried that the Green Party could siphon votes from presidential nominee Joe Biden in the key battleground state.
In two cases, key reports were delayed, with officials suggesting their timing was for political reasons.The Trump administration’s politicization of coronavirus comes to a head | Aaron Blake | September 16, 2020 | Washington Post
Nadia will play a key role in that, both for Slack and for our customers.Slack hires former Live Nation exec as new chief people officer | Michal Lev-Ram, writer | September 16, 2020 | Fortune
With the pandemic still raging, key voters may not be willing to change the subject.Trump, in town hall, says he wouldn’t have done anything differently on pandemic | Colby Itkowitz, Josh Dawsey, Felicia Sonmez, John Wagner | September 16, 2020 | Washington Post
Getting men to do their share of care and domestic work is a key overlooked strategy in reducing poverty.
By contrast, Solomon can tell us a great deal about what really changed the country—because at key moments, he was there.The Real Story Behind the Fight for Marriage Equality | E.J. Graff | December 30, 2014 | THE DAILY BEAST
The second lesson is that no one writing before the twentieth century holds a key to our problems.
As with so many things, keeping screen time in moderate amounts seems key.Yes, Your Toddler Can Watch TV: The New Rules for Screen Time | Russell Saunders | December 26, 2014 | THE DAILY BEAST
The opposition responded with a month-long Occupy Abay (like Occupy Wall St) campaign, in which Udaltsov was one of key figures.Behind Bars for the Holidays: 11 Political Prisoners We Want to See Free In 2015 | Movements.Org | December 25, 2014 | THE DAILY BEAST
Mr. Jones swung round a large iron key he held in his hand, and light dawned upon him.Elster's Folly | Mrs. Henry Wood
Mr. Collingwood, taking the key from his mother, locked the little door in the boarding, after them.The Boarded-Up House | Augusta Huiell Seaman
About her neck was hung a covered basket and a door-key; and Davy at once concluded that she was Sindbad's house-keeper.Davy and The Goblin | Charles E. Carryl
The girl smiled, and drew out a large key, and nodded, still smiling as she replaced it.Checkmate | Joseph Sheridan Le Fanu
The friends were standing close to the wall; but on these sounds they moved away; and a key presently turned in the door.The Pastor's Fire-side Vol. 3 of 4 | Jane Porter
British Dictionary definitions for key (1 of 3)
a metal instrument, usually of a specifically contoured shape, that is made to fit a lock and, when rotated, operates the lock's mechanism
any instrument that is rotated to operate a valve, clock winding mechanism, etc
a small metal peg or wedge inserted into keyways
any of a set of levers operating a typewriter, computer, etc
any of the visible parts of the lever mechanism of a musical keyboard instrument that when depressed set in motion the action that causes the instrument to sound
Also called: tonality any of the 24 major and minor diatonic scales considered as a corpus of notes upon which a piece of music draws for its tonal framework
the main tonal centre in an extended composition: a symphony in the key of F major
the tonic of a major or minor scale
See tuning key
something that is crucial in providing an explanation or interpretation: the key to adult behaviour lies in childhood
a means of achieving a desired end: the key to happiness
a means of access or control: Gibraltar is the key to the Mediterranean
a list of explanations of symbols, codes, etc
a text that explains or gives information about a work of literature, art, or music
Also called: key move the correct initial move in the solution of a set problem
biology a systematic list of taxonomic characteristics, used to identify animals or plants
a hand-operated device for opening or closing a circuit or for switching circuits
a hand-operated switch that is pressed to transmit coded signals, esp Morse code
the grooving or scratching of a surface or the application of a rough coat of plaster, etc, to provide a bond for a subsequent finish
pitch: he spoke in a low key
a characteristic mood or style: a poem in a melancholic key
level of intensity: she worked herself up to a high key
railways a wooden wedge placed between a rail and a chair to keep the rail firmly in place
a wedge for tightening a joint or for splitting stone or timber
short for keystone (def. 1)
botany any dry winged fruit, esp that of the ash
(modifier) photog determining the tonal value of a photograph: flesh colour is an important key tone
of great importance; crucial: a key issue
(foll by to) to harmonize (with): to key one's actions to the prevailing mood
to adjust or fasten with a key or some similar device
to provide with a key or keys
to scratch the paintwork of (a car) with a key
(often foll by up) to locate the position of (a piece of copy, artwork, etc) on a layout by the use of symbols
(also intr) another word for keyboard (def. 3)
to include a distinguishing device in (an advertisement, etc), so that responses to it can be identified
to provide a keystone for (an arch)
- keyless, adjective
British Dictionary definitions for key (2 of 3)
a variant spelling of cay
British Dictionary definitions for Key (3 of 3)
John (Phillip). born 1961, New Zealand politician; prime minister from 2008
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Scientific definitions for key
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for key
The main or central note of a piece of music (or part of a piece of music). Each key has its own scale, beginning and ending on the note that defines the octave of the next scale. The key of C-major uses a scale that starts on C and uses only the white keys of the piano. In a piece composed in the key of C, the music is likely to end on the note C, and certain combinations of notes based on C will predominate.
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Other Idioms and Phrases with key
In addition to the idiom beginning with key
- key up
- in key
- under lock and key
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.