sink - noun

plumbing fixture consisting of a water basin fixed to a wall or floor and having a drainpipe

(technology) a process that acts to absorb or remove energy or a substance from a system

a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof

a covered cistern; waste water and sewage flow into it

sink - verb

• fall or descend to a lower place or level
• cause to sink
• pass into a specified state or condition
• go under,
• descend into or as if into some soft substance or place
• appear to move downward
• fall heavily or suddenly; decline markedly
• fall or sink heavily
• embed deeply

sink - thesaurus

bury   cesspit   cesspool   dip   drop   lapse   pass   settle   sinkhole   slump   subside   sump