To expose one's deception or other wrongdoing. A noun or pronoun can be used between "catch" and "out." I wouldn't lie to the detective—her whole job is to catch you out! The CEO was finally caught out and his embezzlement scandal exposed.

Revealed to have done something, often something undesirable or nefarious. That official has been caught out making inappropriate comments, and yet his colleagues won't take any action against him.