Webster's Revised Unabridged Dictionary · 1913

Mortise

Mortise , noun

[French mortaise; compare Sp. mortaja, Arabic murtazz fixed, or Welsh mortais, Ir. mortis, moirtis, Gael. moirteis.]

A cavity cut into a piece of timber, or other material, to receive something (as the end of another piece) made to fit it, and called a tenon.
Collocations (4)
Mortise and tenon (Carpentry) , made with a mortise and tenon; joined or united by means of a mortise and tenon; -- used adjectively.
Mortise joint , a joint made by a mortise and tenon.
Mortise lock , See under Lock.
Mortise wheel , a cast-iron wheel, with wooden clogs inserted in mortises on its face or edge; -- also called mortise gear, and core gear.

Mortise , transitive verb

1.
To cut or make a mortise in.
2.
To join or fasten by a tenon and mortise; as, to mortise a beam into a post, or a joist into a girder.