plughole

noun

Etymology: From plug + hole.

1. The hole at the bottom of a bath, sink or tub, which can be blocked using a plug; a drain (US)

   “The plughole started to slurp loudly as the water went down it.”

   “He jabbed his fingers into his hair and worked the dirt from the follicles, watched it swirl away down the plughole, sandy granules, flakes of dust and ash.”