From Longman Dictionary of Contemporary Englishlaugh something ↔ off phrasal verbSERIOUS/NOT JOKINGto pretend that something is less serious than it really is by laughing or joking about it Knox laughed off rumors that he would be running for mayor. → laugh→ See Verb table
Examples from the Corpus
laugh off• By this time Irene was emitting a steady gurgle of contentment, when she wasn't laughing her head off.• Louise: Ursula would have laughed her head off.• Joey stood in the door laughing his head off and Noreen peered over his shoulder, her hands over her mouth.• We laugh it off as a bunch of California New Age woo-woos playing with rocks.• She'd laughed her head off at his contribution to the couplet, and now she'd sent it in.• She had laughed it off, but I fancied she had found the situation embarrassing.• Old Warleigh would laugh his head off if I put reasons like that to him.• She laughed and rushed off, late, to her costume fitting. 