noun
mortise; mortice
A rectangular hole cut into a piece of wood to receive a tenon (枘/ほぞ) in joinery. Technical term used in architecture and woodworking.
See also: 枘
ほぞ穴にほぞを差し込んで固定する。
Insert the tenon into the mortise and secure it.
この家具はほぞ穴とほぞだけで組み立てられている。
This piece of furniture is assembled using only mortise and tenon joints.
ほぞ (tenon) is the projecting part that fits into the ほぞ穴 (mortise). Together they form a ほぞ継ぎ (mortise and tenon joint).
Compound of ほぞ (tenon) and 穴 (hole). The kanji 枘 specifically means tenon, but is rarely used.