from
The Collaborative International Dictionary of English v.0.48
Mortise \Mor"tise\, n. [F. mortaise; cf. Sp. mortaja, Ar.
murtazz fixed, or W. 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.
[1913 Webster]
{Mortise and tenon} (Carp.), 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}.
[1913 Webster]