Definition from Wiktionary, the free dictionary
smell a rat
- (idiomatic) To sense something suspicious.
- 1663, John Dryden, The Wild Gallant: A Comedy, act 4, sc. 1:
- Oh, are you thereabouts, sir? then I smell a rat, i’faith; but I'll say nothing.
- 1874, Anthony Trollope, Phineas Redux, ch. 40:
- Mr. Gresham, when he heard this, thought that he began to smell a rat, and was determined to be on his guard.
to sense something suspicious