drain

(chiefly US, Canada) A conduit allowing liquid to flow out of an otherwise contained volume; a plughole (UK)

(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.

Something consuming resources and providing nothing in return.

(vulgar) An act of urination.

(electronics) One terminal of a field effect transistor (FET).

(pinball) An outhole.

(UK, slang, dated) A drink.