A pipe fitting or spout with a curved shape, used in plumbing and drainage. The term can refer to an elbow joint in piping, a gooseneck-shaped spout, or a rainspout that directs water away from a building.
The rainspout's elbow is clogged.
We need to replace the elbow in the piping.
呼び (yobi, 'calling' or 'drawing') + 樋 (toi, 'gutter' or 'pipe'). The exact derivation is uncertain, but it likely refers to a pipe fitting that 'draws' water in a particular direction.