sink

a covered cistern

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

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

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

fall heavily or suddenly

embed deeply

descend into or as if into some soft substance or place

pass into a specified state or condition

fall or descend to a lower place or level

cause to sink

fall or sink heavily

go under, 'The raft sank and its occupants drowned'

appear to move downward