Toilet

A toilet (also called the head) was a device used to dispose of bodily wastes.

In 2020, the crew of the USS Lewis & Clark detected their stowaway, Zoe Querez, because she flushed the toilet aboard ship. 

In 2151, Worley Elementary School sent letters and questions to the Enterprise (NX-01). One of the questions was "When you flush the toilet, where does it go?" Captain Jonathan Archer had Chief engineer Trip Tucker explain the ship's process of biomatter resequencing to the class.