waste pipe

WordReference Random House Unabridged Dictionary of American English © 2026

waste′ pipe′, 

1. Building a pipe for draining liquid waste or excess liquids.
2. Building [Plumbing.] a pipe for draining away the wastes of a building other than those from water closets. Cf. soil pipe. 
• 1505–15

Collins Concise English Dictionary © HarperCollins Publishers::

waste pipe noun

1. a pipe to take excess or used water away, as from a sink to a drain