Množina: mortises
ETYM French mortaise; cf. Spanish mortaja, Arabic murtazz fixed, or W. mortais, Irish mortis, moirtis, Gael. moirteis.
A square hole made to receive a tenon and so to form a joint; SYN. mortice.
Hole or recess made in wood to receive a tenon.
To cut a mortise in; SYN. mortice.