go down the drain

Từ điển Oxford Advanced Learner 8th

(go) down the ˈdrain idiom
(BrE also (go) down the ˈplughole) (informal)(to be) wasted; (to get) very much worse
•It's just money down the drain, you know.
•Safety standards have gone down the drain.
Main entry: ↑drain_idiom