Essential

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

• 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)

• something crucial for explaining

• pitch of the voice

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

• a kilogram of a narcotic drug

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

• a coral reef off the southern coast of Florida

• (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

• a list of answers to a test

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

• a generic term for any device whose possession entitles the holder to a means of access

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

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

• a lever (as in a keyboard) that actuates a mechanism when depressed

• serving as an essential component

• identify as in botany or biology, for example

• provide with a key

• vandalize a car by scratching the sides with a key

• regulate the musical pitch of

• harmonize with or adjust to

• a necessary or essential thing

• grape juice before or during fermentation

• the quality of smelling or tasting old or stale or mouldy

• highly recommended

• requiring attention or action

• relating to verbs in the imperative mood

• a mood that expresses an intention to influence the listener's behavior

• some duty that is essential and urgent

• a verb in the imperative mood.