(biology) A written tool for identification of plants and animals. It is written as a sequence of paired questions, the choice of which determines the next pair of questions until a name or identification is reached.

A very simple design of key that usually has a cylindrical shaft (sometimes called a "shank") and a single, minimal flat, rectangular tooth or "bit".

(music) A key using alternative fingerings for certain notes on woodwind instruments. Specifically, a key that is located between the first and second keys operated by the left hand on a saxophone. Pressing LH1 and the bis key simultaneously results in the sounding of a Bb. This is especially useful when playing in keys with many flats.

(aviation, slang) The large white striped section at the ends of a runway, used as a landing aiming point and as a distance indicator.

(UK) A hex head wrench.

(Canada, US, colloquial) Kind of. / (slang) In a low-key or surreptitious manner; secretively; on the down-low.

(art, photography) Dark; characterised by dark tones and muted colours. / (by extension) Restrained, subtle, not trying to attract attention.

A hex head wrench.

The depression of an input key; a keystroke. / (computing) The buffered electrical signal resulting from such an event, sometimes distinguished from the release.

plural of key press