Toilet seat

A toilet seat is a hinged unit consisting of a seat, and usually a lid, which is bolted onto a toilet bowl for a toilet used in a sitting position (as opposed to a squat toilet). The seat can be either for a flush toilet or a dry toilet. A toilet seat consists of the seat itself, which may be contoured for the user to sit on, and the lid, which covers the toilet when it is not in use – the lid may be absent in some cases, particularly in public restrooms. When the lid is down, the lid itself is also used as a seat when needed.

https://en.wikipedia.org/wiki/Toilet_seat