key

An object designed to open and close a lock.

An object designed to fit between two other objects (such as a shaft and a wheel) in a mechanism and maintain their relative orientation.

A crucial step or requirement.

A guide explaining the symbols or terminology of a map or chart; a legend.

A guide to the correct answers of a worksheet or test.

One of several small, usually square buttons on a typewriter or computer keyboard, mostly corresponding to text characters.

In musical instruments, one of the valve levers used to select notes, such as a lever opening a hole on a woodwind.

In instruments with a keyboard such as an organ or piano, one of the levers, or especially the exposed front end of it, which are depressed to cause a particular sound or note to be produced.

The lowest note of a scale; keynote.

In musical theory, the total melodic and harmonic relations, which exist between the tones of an ideal scale, major or minor; tonality.

In musical theory and notation, the tonality centering in a given tone, or the several tones taken collectively, of a given scale, major or minor.

In musical notation, a sign at the head of a staff indicating the musical key.

The general pitch or tone of a sentence or utterance.

A modification of an advertisement so as to target a particular group or demographic.

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

A manual electrical switching device primarily used for the transmission of Morse code.

A piece of information (e.g. a passphrase) used to encode or decode a message or messages.

A password restricting access to an IRC channel.

In a relational database, a field used as an index into another table (not necessarily unique).

A value that uniquely identifies an entry in a container.

The free-throw lane together with the circle surrounding the free-throw line, the free-throw lane having formerly been narrower, giving the area the shape of a skeleton key hole.

A series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon.

A piece of wood used as a wedge.

The last board of a floor when laid down.

A keystone.

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

A wooden support for a rail on the bullhead rail system.

The degree of roughness, or retention ability of a surface to have applied a liquid such as paint, or glue.

The thirty-third card of the Lenormand deck.

(print and film) The black ink layer, especially in relation to the three color layers of cyan, magenta, and yellow. See also CMYK.

A color to be masked or made transparent.