catch somebody out

From King Dictionary of Contemporary Englishcatch somebody out phrasal verb1 MISTAKEto make someone make a mistake, especially deliberately and in order to prove that they are lying The interviewer may try to catch you out.2 READYif something unexpected catches you out, it puts you in a difficult situation because you were not expecting it or not fully prepared for it Even the best whitewater rafters get caught out by the fierce rapids here. catch→ See Verb table
Examples from the Corpus
catch outAnyone caught visiting the Bookman during these was automatically punished and he kept swapping them around to try and catch people out.Porfiry uses them to try and catch Raskolnikov out.Some of the old inspectors tried to catch you out.The Corporal fired questions at me, all the time trying to catch me out.But they are there, waiting to catch you out and to make you ill.Once, when dusk caught us miles out in the country, an old couple took us in for the night.A: You try and catch me out, Mr Vansitart.Jody is following the ball, but she catches Red out of the corner of her eye.