A plant sink is a storage center in plants to hold sugars, normally the roots of the plant

Carbon dioxide sink, any storage of nutrients or a place of CO2 storage

Sink is the name of a game generally played by Discordians.

Heat sink, an environment or object capable of absorbing heat from another object with which it is in thermal contact

Sink, a bowl-shaped fixture, usually made of porcelain or stainless steel, that is used for washing hands or small objects

Sink (geography), an area of dry land below sea-level, for example the Salton Sink

sink (computing), in software engineering, an object implementing the event interface to receive incoming events

Robert Sink, led the 506th Parachute Infantry Regiment in the Band of Brothers