1
general::
Phrase(s): down the drain
Fig. gone; wasted. • Well, there’s 400 bucks down the drain. • A lot of money went down the drain in that Wilson deal.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
On the way to being lost or wasted; disappearing. For example, Buying new furniture when they can't take it with them is just pouring money down the drain, or During the Depression huge fortunes went down the drain. This metaphoric term alludes to water going down a drain and being carried off. [Colloquial; c. 1920] For a synonym, see DOWN THE TUBES.
American Heritage Idioms