sink (Noun) — Plumbing fixture consisting of a water basin fixed to a wall or floor and having a drainpipe.
sink (Noun) — (technology) a process that acts to absorb or remove energy or a substance from a system. ex. "the ocean is a sink for carbon dioxide"
sink (Noun) — A depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof.
sink (Noun) — A covered cistern; waste water and sewage flow into it.
sink (Verb) — Fall or descend to a lower place or level. ex. "He sank to his knees"
sink (Verb) — Cause to sink. ex. "The Japanese sank American ships in Pearl Harbor"
sink (Verb) — Pass into a specified state or condition. ex. "He sank into nirvana"
sink (Verb) — Go under. ex. "The raft sank and its occupants drowned"
sink (Verb) — Descend into or as if into some soft substance or place. ex. "He sank into bed"
sink (Verb) — Appear to move downward. ex. "The setting sun sank below the tree line"
sink (Verb) — Fall heavily or suddenly; decline markedly. ex. "The real estate market sank"
sink (Verb) — Fall or sink heavily. ex. "My spirits sank"
sink (Verb) — Embed deeply. ex. "She sank her fingers into the soft sand"