noun
cross-piece joining boards (carpentry)
Specialized carpentry term for a cross-piece that joins two or more boards together.
この棚の裏側には、板を固定するための端喰が打ち付けられている。
On the back of this shelf, a cross-piece is nailed to secure the boards.
The exact derivation is uncertain; the kanji 端 (edge) and 喰 (eat/bite) may relate to the piece 'biting' into the edges of boards.