v. & n.
v. 1 tr. draw off liquid from, esp.: a make (land etc.) dry by providing an outflow for moisture. b (of a river) carry off the superfluous water of (a district). c remove purulent matter from (an abscess). 2 tr. (foll. by off, away) draw off (liquid) esp. by a pipe. 3 intr. (foll. by away, off, through) flow or trickle away. 4 intr. (of a wet cloth, a vessel, etc.) become dry as liquid flows away (put it there to drain). 5 tr. (often foll. by of) exhaust or deprive (a person or thing) of strength, resources, property, etc. 6 tr. a drink (liquid) to the dregs. b empty (a vessel) by drinking the contents.
n. 1 a a channel, conduit, or pipe carrying off liquid, esp. an artificial conduit for water or sewage. b a tube for drawing off the discharge from an abscess etc. 2 a constant outflow, withdrawal, or expenditure (a great drain on my resources). down the drain colloq. lost, wasted. laugh like a drain laugh copiously; guffaw.
[ OE dre(a)hnian f. Gmc ]