Definify.com

Webster 1913 Edition

Noun.

A hole or apertupe in a door or lock, for receiving a key.

(a)

(Carp.)

A hole or excavation in beams intended to be joined together, to receive the key which fastens them.

(b)

(Mach.)

a mortise for a key or cotter.

Keyhole limpet

(Zool.)

a marine gastropod of the genus Fissurella and allied genera. See

–

Keyhole saw

a narrow, slender saw, used in cutting keyholes, etc., as in doors; a kind of compass saw or fret saw.

–

Keyhole urchin

(Zool.)

any one of numerous clypeastroid sea urchins, of the genera

Melitta

Rotula

, and

Encope

; – so called because they have one or more perforations resembling keyholes.

Noun.

A hole or aperture in a door or lock, for receiving a key.