adj 1: 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" [syn: cardinal
2: effective; producing a desired effect; "the operative word"
n 1: metal device shaped in such a way that when it is inserted
into the appropriate lock the lock's mechanism can be
2: something crucial for explaining; "the key to development is
3: pitch of the voice; "he spoke in a low key"
4: any of 24 major or minor diatonic scales that provide the
tonal framework for a piece of music [syn: tonality
5: one thousand grams; the basic unit of mass adopted under the
System International d'Unites; "a kilogram is
approximately 2.2 pounds"; "they were carrying two keys of
heroin" [syn: kilogram
6: 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) [syn: Key
7: a coral reef off the southern coast of Florida [syn: cay
8: a list of words or phrases that explain symbols or
9: mechanical device used to wind another device that is driven
by a spring (as a clock) [syn: winder
10: a lever that actuates a mechanism when depressed
v 1: as in in botany or biology, for example [syn: identify
2: provide with a key; "We were keyed after the locks were
changed in the building"
3: vandalize a car by scratching the sides with a key"
4: regulate the musical pitch of
5: harmonize with or adjust to; "key one's actions to the
voters' prevailing attitude"