drain

Etymology

From Middle English dreinen, from Old English drēahnian (“to drain, strain, filter”), from Proto-Germanic *drauhnōną (“to strain, sieve”), from Proto-Germanic *draugiz (“dry, parched”). Akin to Old English drūgian (“to dry up”), Old English drūgaþ (“dryness, drought”), Old English drȳġe (“dry”). More at dry.

noun

1. (chiefly US, Canada) A conduit allowing liquid to flow out of an otherwise contained volume; a plughole (UK)
   The drain in the kitchen sink is clogged.
   An extreme version of vorticity is a vortex. The vortex is a spinning, cyclonic mass of fluid, which can be observed in the rotation of water going down a drain, as well as in smoke rings, tornados and hurricanes. 2013-03, Frank Fish, George Lauder, “Not Just Going with the Flow”, in American Scientist, volume 101, number 2, page 114
2. (chiefly UK) An access point or conduit for rainwater that drains directly downstream in a (drainage) basin without going through sewers or water treatment in order to prevent or belay floods.
3. Something consuming resources and providing nothing in return.
   That rental property is a drain on our finances.
4. (vulgar) An act of urination.
5. (electronics) One terminal of a field effect transistor (FET).
6. (pinball) An outhole.
7. (UK, slang, dated) A drink.
   What did she want with money, except now and then for a drain of white satin. 1966, Henry Mayhew, Peter Quennell, London's Underworld, page 48

verb

1. (intransitive) To lose liquid.
   The clogged sink drained slowly.
   Knock knock. / Who’s there? / Dwayne. / Dwayne who? / Drain the bathtub, I’m drowning.
2. (intransitive) To flow gradually.
   The water of low ground drains off.
3. (transitive, ergative) To cause liquid to flow out of.
   Please drain the sink. It’s full of dirty water.
4. (transitive, ergative) To convert a perennially wet place into a dry one.
   They had to drain the swampy land before the parking lot could be built.
5. (transitive) To deplete of energy or resources.
   The stress of this job is really draining me.
6. (transitive) To draw off by degrees; to cause to flow gradually out or off; hence, to exhaust.
7. (transitive, obsolete) To filter.
8. (intransitive, pinball) To fall off the bottom of the playfield.
   When a ball finally drains, it's gulped down by a giant gator beneath the set of flippers. 1990, Steven A. Schwartz, Compute's Nintendo Secrets
9. (slang, archaic, transitive) To drink.
   But when I strove my flame to tell, / Says she, 'Come, stow that patter, / If you're a cove wot likes a gal, / Vy don't you stand some gatter?' / In course I instantly complied— / Two brimming quarts of porter, / With sev'ral goes of gin beside, / Drain'd Bet the Coaley's daughter. Bet the Coaley's Daughter (traditional song)