{adj.} or {adv. phr.}, {informal} Wasted; lost. * /It is money down the drain if you spend it all on candy./ * /Our plans to go swimming went down the drain when it rained./ Compare: GO BY THE BOARD.
DOWN THE DRAIN
Meaning of DOWN THE DRAIN in English
Slang English vocab. Английский сленговый словарь. 2012