noun
A sloping beam that supports a roof, typically used in traditional Japanese architecture.
古い家の垂木が傷んでいた。
The rafters of the old house were damaged.
垂木に瓦を載せる前に防水シートを敷く。
Before placing the tiles on the rafters, lay down a waterproof sheet.
Rarely used kanji form for 'rafter'.
The origin is uncertain, but the word is native Japanese. The kanji 垂 (hang down) and 木 (wood) describe the sloping wooden beams.