It's a bust
I believe the answer is:
raid
'it's a bust' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for raid that I've seen before include "Sally" , "Rapid surprise attack" , "Finch and Bronson starred in . . . . On Entebbe" , "Smash-and-grab?" , "Foray, sudden attack" .)