Results for: key
1. (Engineering / Mechanical Engineering) a metal instrument, usually of a specifically contoured shape, that is made to fit a lock and, when rotated, operates the locks mechanism
2. (Engineering / Mechanical Engineering) any instrument that is rotated to operate a valve, clock winding mechanism, etc.
3. (Engineering / Mechanical Engineering) a small metal peg or wedge inserted into keyways
4. (Engineering / Mechanical Engineering) any of a set of levers operating a typewriter, computer, etc.
5. (Music / Instruments) 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
6. (Music / Classical Music)
a. 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
b. the main tonal centre in an extended composition a symphony in the key of F major
c. the tonic of a major or minor scale
d. See tuning key
7. something that is crucial in providing an explanation or interpretation the key to adult behaviour lies in childhood
8. a means of achieving a desired end the key to happiness
9. a means of access or control Gibraltar is the key to the Mediterranean
10. a list of explanations of symbols, codes, etc.
11. a text that explains or gives information about a work of literature, art, or music
12. Also called key move the correct initial move in the solution of a set problem
13. (Life Sciences & Allied Applications / Biology) Biology a systematic list of taxonomic characteristics, used to identify animals or plants
14. (Miscellaneous Technologies / Photography) Photog Painting the dominant tonal value and colour intensity of a picture See also low-key  high-key
15. (Engineering / Electrical Engineering) Electrical engineering
a. a hand-operated device for opening or closing a circuit or for switching circuits
b. a hand-operated switch that is pressed to transmit coded signals, esp Morse code
16. (Miscellaneous Technologies / Building) 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
17. pitch he spoke in a low key
18. a characteristic mood or style a poem in a melancholic key
19. level of intensity she worked herself up to a high key
20. (Transport / Railways) Railways a wooden wedge placed between a rail and a chair to keep the rail firmly in place
21. (Miscellaneous Technologies / Building) a wedge for tightening a joint or for splitting stone or timber
22. (Miscellaneous Technologies / Building) short for keystone 
23. (Life Sciences & Allied Applications / Botany) Botany any dry winged fruit, esp that of the ash
24. (modifier) of great importance a key issue
25. (Miscellaneous Technologies / Photography) (modifier) Photog determining the tonal value of a photograph flesh colour is an important key tone
vb (mainly tr)
1. (foll by to) to harmonize (with) to key ones actions to the prevailing mood
2. to adjust or fasten with a key or some similar device
3. to provide with a key or keys
4. (Law) to scratch the paintwork of (a car) with a key
5. (Communication Arts / Printing, Lithography & Bookbinding) (often foll by up) to locate the position of (a piece of copy, artwork, etc.) on a layout by the use of symbols
6. (Electronics & Computer Science / Computer Science) (also intr) another word for keyboard 
7. to include a distinguishing device in (an advertisement, etc.), so that responses to it can be identified
(Earth Sciences / Physical Geography) a variant spelling of cay
key /ki/ n. 1 a thin piece of metal used to lock or unlock a door, start or stop an engine, etc.: I opened the front door with my key. 2 fig. the most important part of s.t.: The key to success is hard work. 3 a written guide that explains the meaning of s.t.: This key explains how to read the symbols on the map. 4 in music, a group of notes related to and named after the lowest note in the group: That song is written in the key of B flat. 5 a part of a machine or musical instrument that is pressed down to make it work: She pressed a computer key and typed a letter. 6 a small low island: We went camping in the Florida Keys last summer.
v. 1 [T] to test musical instruments to make sure that they will sound good together: Musicians in the band keyed their guitars before playing. 2 to be keyed up: to be excited or nervous: She is always keyed up before a test.
adj. very important, essential: Cotton is a key industry in the South.