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

Noun
a lever that actuates a mechanism when depressed

Noun
the central building block at the top of an arch or vault

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

Noun
pitch of the voice; "he spoke in a low key"

Noun
something crucial for explaining; "the key to development is economic integration"

Noun
a generic term for any device whose possession entitles the holder to a means of access; "a safe-deposit box usually requires two keys to open it"

Noun
a list of words or phrases that explain symbols or abbreviations

Noun
a list of answers to a test; "some students had stolen the key to the final exam"

Noun
any of 24 major or minor diatonic scales that provide the tonal framework for a piece of music

Noun
(basketball) a space (including the foul line) in front of the basket at each end of a basketball court; usually painted a different color from the rest of the court; "he hit a jump shot from the top of the key"; "he dominates play in the paint"

Noun
a coral reef off the southern coast of Florida

Noun
United States lawyer and poet who wrote a poem after witnessing the British attack on Baltimore during the War of 1812; the poem was later set to music and entitled `The Star-Spangled Banner'' (1779-1843)

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

Noun
a kilogram of a narcotic drug; "they were carrying two keys of heroin"

Verb
harmonize with or adjust to; "key one''s actions to the voters'' prevailing attitude"

Verb
regulate the musical pitch of

Verb
identify as in botany or biology, for example

Verb
vandalize a car by scratching the sides with a key; "His new Mercedes was keyed last night in the parking lot"

Verb
provide with a key; "We were keyed after the locks were changed in the building"

Adjective S.
serving as an essential component; "a cardinal rule"; "the central cause of the problem"; "an example that was fundamental to the argument"; "computers are fundamental to modern industrial structure"

Adjective S.
effective; producing a desired effect; "the operative word"

n.
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.

n.
An instrument which is turned like a key in fastening or adjusting any mechanism; as, a watch key; a bed key, etc.

n.
That part of an instrument or machine which serves as the means of operating it; as, a telegraph key; the keys of a pianoforte, or of a typewriter.

n.
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.

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

n.
A piece of wood used as a wedge.

n.
The last board of a floor when laid down.

n.
A keystone.

n.
That part of the plastering which is forced through between the laths and holds the rest in place.

n.
A wedge to unite two or more pieces, or adjust their relative position; a cotter; a forelock.

n.
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.

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

n.
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 as " sharp four," "flat seven," etc. Scales and tunes of every variety are made from the tones of a key.

n.
The fundamental tone of a movement to which its modulations are referred, and with which it generally begins and ends; keynote.

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

v. t.
To fasten or secure firmly; to fasten or tighten with keys or wedges.

Key

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

Who keeps the keys of all the creeds.

Both warbling of one song, both in one key.

You fall at once into a lower key.

Key

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.

To fasten or secure firmly; to fasten or tighten with keys or wedges.