key
noun
1.
2.
something crucial for explaining
3.
4.
5.
a kilogram of a narcotic drug
7.
a coral reef off the southern coast of Florida
8.
(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
9.
a list of answers to a test
10.
a list of words or phrases that explain symbols or abbreviations
11.
a generic term for any device whose possession entitles the holder to a means of access
12.
mechanical device used to wind another device that is driven by a spring (as a clock)
14.
a lever (as in a keyboard) that actuates a mechanism when depressed