Definition of "Key" :

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 (as in a keyboard) 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."

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: serving as an essential component