An English and Scottish surname transferred from the given name derived from the given name Alan.

(colloquial) Short for Allen wrench.

(organic chemistry) Any of a class of hydrocarbons having two double bonds from one carbon atom to two others - R₂C=C=CR₂; especially the parent compound CH₂=C=CH₂ (propadiene).

plural of allene

Characteristic of an allene

A female given name

plural of Allen

plural of Allen

A bolt whose head has a hexagonal socket.

(US) A hex head wrench.