Sink
In plumbing, a sink is a bowl-shaped fixture, usually made of porcelain (or, especially in the kitchen, stainless steel), that is used for washing hands or small objects such as dishes, nylons, socks or underwear. Old sinks were often made of enameled steel or cast iron. In American plumbing parlance, a bathroom sink is known as a lavatory. Sinks generally have faucets, usually cold and hot, and a drain. When a sink becomes stopped-up or clogged, a person will often resort to use of chemical drain cleaner or a plunger.See also
In electromagnetic theory sink and source are respectively the termination or supply of current flow; the divergence of the current density is their negative and positive, respectively.
More generally this idea can be applied to vector fields other than current density; for example, mass is a sink of gravitational field strength.
A TTL (Transistor Transistor Logic) circuit will "sink" current when the circuit is a logic "0" (grd) and "source" current at a logic "1" (+5vdc).
[These terms are far more generally used than just in digital electronics. Indeed, they antedate digital electronics. They are used in thermodynamics, which originated in the 19th century, and also for other physical systems such as rivers. Would some physicist complete this article?]
Other uses of the general scientific concept of a sink are the heat sink and the CO2 sink.