Dictionary > English Dictionary > Definition, synonym and antonym of key
Meaning of key by Wiktionary Dictionary


    A numeric keypad with 16 keys
    The keys of a musical keyboard.


    • ( RP, US ) enPR: kē, IPA: /kiː/, X-SAMPA: /ki:/
    • Rhymes: -iː
    • Homophone: cay ( one pronunciation ), quay

    Etymology 1

    From Middle English keye, kaye, keiȝe, from Old English cǣġ, cǣġe, cǣga ( “key, solution, experiment” ), from Proto-Germanic *kēkaz ( “stake, post, pole” ), from Proto-Indo-European *ǵogh-, *ǵegh- ( “branch, stake, bush” ), related to Old English cǣggian ( “to lock, shut” ). Cognate with Scots key, kay ( “key” ), West Frisian kaai ( “key” ), North Frisian kay ( “key” ), Middle Low German kāk ( “whipping post, pillory” ), and perhaps to Middle Dutch keige ( “javelin, spear” ), Middle Low German keie, keige ( “spear” ) .


    key ( plural: keys )

    1. An object designed to open and close a lock .
    2. An object designed to fit between two other objects ( such as a shaft and a wheel ) in a mechanism and maintain their relative orientation .
    3. A crucial step or requirement .
      the key to solving this problem.. .
      the key to winning this game
    4. A guide explaining the symbols or terminology of a map or chart; a legend .
      The key says that A stands for the accounting department .
    5. A guide to the correct answers of a worksheet or test .
      Some students cheated by using the answer key .
    6. ( computing ) One of several small, usually square buttons on a typewriter or computer keyboard, mostly corresponding to text characters .
      Press the Escape key .
    7. ( music ) One of a number of rectangular moving parts on a piano or musical keyboard, each causing a particular sound or note to be produced .
    8. ( music ) One of various levers on a musical instrument used to select notes, such as a lever opening a hole on a woodwind .
    9. ( music ) A hierarchical scale of musical notes on which a composition is based
      the key of B-flat major
    10. ( historical ) A manual electrical switching device primarily used for the transmission of Morse code .
    11. ( cryptography ) A piece of information ( e.g. a passphrase ) used to encode or decode a message or messages .
    12. ( computing ) In a relational database, a field used as an index into another table ( not necessarily unique ) .
    13. ( computing ) A value that uniquely identifies an entry in an associative array .
    14. ( basketball ) The free-throw lane together with the circle surrounding the free-throw line, the free-throw lane having formerly been narrower, giving the area the shape of a skeleton key hole .
      He shoots from the top of the key .
    15. ( biology ) A series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon .
    16. ( slang ) kilogram
    Derived terms
    See also
    • clef
    • scale
    • Key on Wikipedia .
    • wikisource-logo.svg Key in the 1911 Encyclopædia Britannica .


    key ( comparative more key, superlative most key )

    1. Indispensable .
      He is the key player for his soccer team .
      He is the key witness .
    2. Important, salient .
      She makes several key points


    key ( third-person singular simple present keys present participle keying, simple past and past participle keyed )

    1. To fit ( a lock ) with a key .
    2. To fit ( pieces of a mechanical assembly ) with a key to maintain the orientation between them .
    3. To mark or indicate with a symbol indicating membership in a class.
    4. ( telegraphy and radio telegraphy ) To depress ( a telegraph key ) .
    5. ( radio ) To operate ( the transmitter switch of a two-way radio ) .
    6. ( computing ) ( more usually to key in ) To enter ( information ) by typing on a keyboard or keypad .
      Our instructor told us to key in our user IDs .
    7. ( colloquial ) To vandalize ( a car, etc. ) by scratching with an implement such as a key .
      He keyed the car that had taken his parking spot .
    8. To link ( as one might do with a key or legend ).
    9. ( intransitive ) ( biology, chiefly taxonomy ) To be identified as a certain taxon when using a key .
    Derived terms

    Etymology 2

    Variant of cay, from Spanish cayo .

    Alternative form


    key ( plural: keys )

    1. One of a string of small islands .
      "the Florida Keys"


Explanation of key by Wordnet Dictionary


    1. harmonize with or adjust to

    2. key one's actions to the voters' prevailing attitude
    3. regulate the musical pitch of

    4. identify as in botany or biology, for example

    5. vandalize a car by scratching the sides with a key

    6. His new Mercedes was keyed last night in the parking lot
    7. provide with a key

    8. We were keyed after the locks were changed in the building
    1. serving as an essential component

    1. metal device shaped in such a way that when it is inserted into the appropriate lock the lock's mechanism can be rotated

    2. a lever ( as in a keyboard ) that actuates a mechanism when depressed

    3. the central building block at the top of an arch or vault

    4. mechanical device used to wind another device that is driven by a spring ( as a clock )

    5. pitch of the voice

    6. he spoke in a low key
    7. something crucial for explaining

    8. the key to development is economic integration
    9. a generic term for any device whose possession entitles the holder to a means of access

    10. a safe-deposit box usually requires two keys to open it
    11. a list of words or phrases that explain symbols or abbreviations

    12. a list of answers to a test

    13. some students had stolen the key to the final exam
    14. any of 24 major or minor diatonic scales that provide the tonal framework for a piece of music

    15. a space ( including the foul line ) in front of the basket at each end of a basketball court

    16. he hit a jump shot from the top of the key
    17. a coral reef off the southern coast of Florida

    18. United States lawyer and poet who wrote a poem after witnessing the British attack on Baltimore during the War of 1812

    19. a winged often one-seed indehiscent fruit as of the ash or elm or maple

    20. a kilogram of a narcotic drug

    21. they were carrying two keys of heroin

    Definition of key by GCIDE Dictionary


    1. Cotter ( kŏttẽr ), n.
      1. A piece of wood or metal, commonly wedge-shaped, used for fastening together parts of a machine or structure. It is driven into an opening through one or all of the parts. [See Illust.] In the United States a cotter is commonly called a key.

      2. A toggle.

    2. Key ( kē ), n. [OE. keye, key, kay, AS. cæg.]
      1. An instrument by means of which the bolt of a lock is shot or drawn; usually, a removable metal instrument fitted to the mechanism of a particular lock and operated by turning in its place.

      2. A small device which is inserted into a mechanism and turned like a key to fasten, adjust, or wind it; as, “a watch key; a bed key; the winding key for a clock, etc.”

      3. One of a set of small movable parts on an instrument or machine which, by being depressed, serves as the means of operating it; the complete set of keys is usually called the keyboard; as, “the keys of a piano, an organ, an accordion, a computer keyboard, or of a typewriter.” The keys may operate parts of the instrument by a mechanical action, as on a piano, or by closing an electrical circuit, as on a computer keyboard. See also senses 12 and 13.

      4. A position or condition which affords entrance, control, pr possession, etc.; as, “the key of a line of defense; the key of a country; the key of a political situation”. Hence, that which serves to unlock, open, discover, or solve something unknown or difficult; as, “the key to a riddle; the key to a problem.” Similarly, see also senses 14 and 15.

      Those who are accustomed to reason have got the true key of books. Locke.

      Who keeps the keys of all the creeds. Tennyson.

      5. That part of a mechanism which serves to lock up, make fast, or adjust to position.

      6. ( Arch. ) A piece of wood used as a wedge. The last board of a floor when laid down.

      7. ( Masonry ) A keystone. That part of the plastering which is forced through between the laths and holds the rest in place.

      8. ( Mach. ) A wedge to unite two or more pieces, or adjust their relative position; a cotter; a forelock. See Illusts. of Cotter, and Gib. A bar, pin or wedge, to secure a crank, pulley, coupling, etc., upon a shaft, and prevent relative turning; sometimes holding by friction alone, but more frequently by its resistance to shearing, being usually embedded partly in the shaft and partly in the crank, pulley, etc.

      9. ( Bot. ) An indehiscent, one-seeded fruit furnished with a wing, as the fruit of the ash and maple; a samara; -- called also key fruit.

      10. ( Mus. ) A family of tones whose regular members are called diatonic tones, and named key tone ( or tonic ) or one ( or eight ), mediant or three, dominant or five, subdominant or four, submediant or six, supertonic or two, and subtonic or seven. Chromatic tones are temporary members of a key, under such names assharp four,” “flat seven,” etc. Scales and tunes of every variety are made from the tones of a key. The fundamental tone of a movement to which its modulations are referred, and with which it generally begins and ends; keynote.

      Both warbling of one song, both in one key. Shak.

      11. Fig: The general pitch or tone of a sentence or utterance.

      You fall at once into a lower key. Cowper.

      12. ( Teleg. ) A metallic lever by which the circuit of the sending or transmitting part of a station equipment may be easily and rapidly opened and closed; as, “a telegraph key”.

      13. any device for closing or opening an electric circuit, especially as part of a keyboard, as that used at a computer terminal or teletype terminal.

      14. A simplified version or analysis which accompanies something as a clue to its explanation, a book or table containing the solutions to problems, ciphers, allegories, or the like; or ( Biol. ) a table or synopsis of conspicuous distinguishing characters of members of a taxonomic group.

      15. ( Computers ) A word or other combination of symbols which serves as an index identifying and pointing to a particular record, file, or location which can be retrieved and displayed by a computer program; as, “a database using multi-word keys”. When the key is a word, it is also called a keyword.

      Key bed. Same as Key seat. -- Key bolt, a bolt which has a mortise near the end, and is secured by a cotter or wedge instead of a nut. Key bugle. See Kent bugle. -- Key of a position or Key of a country. ( Mil. ) See Key, 4. -- Key seat ( Mach. ), a bed or groove to receive a key which prevents one part from turning on the other. -- Key way, a channel for a key, in the hole of a piece which is keyed to a shaft; an internal key seat; -- called also key seat. -- Key wrench ( Mach. ), an adjustable wrench in which the movable jaw is made fast by a key. -- Power of the keys ( Eccl. ), the authority claimed by the ministry in some Christian churches to administer the discipline of the church, and to grant or withhold its privileges; -- so called from the declaration of Christ, “I will give unto thee the keys of the kingdom of heaven.” Matt. xvi. 19.

    3. Key v. t. [imp. & p. p. Keved ; p. pr. & vb. n. Keying.]
      1. To fasten or secure firmly; to fasten or tighten with keys or wedges. Francis.

      2. ( Computers ) To enter ( text, data ) using keys, especially those on a keyboard; to keyboard; as, “to key the data in by hand”.

      3. To adjust so as to be maximally effective in a particular situation; -- of actions, plans, or speech; as, “to key one's campaign speech to each local audience”.

      4. To furnish with a key or keys.

      To key up. ( Arch. ) To raise ( the whole ring of an arch ) off its centering, by driving in the keystone forcibly. ( Mus. ) To raise the pitch of. Hence, ( fig. ), to produce nervous tension in; as, “the whole team was keyed up for the championship game”.

    4. key a. Essential; most important; as, “the key fact in the inquiry; the president was the key player inthe negotiations”.

    5. Quay n. [F. quai. See Key quay.] A mole, bank, or wharf, formed toward the sea, or at the side of a harbor, river, or other navigable water, for convenience in loading and unloading vessels. [Written also key.]