#1 burst out v. give sudden release to an expression; "We burst out laughing"; "'I hate you. wn #2 burst out v. appear suddenly; "Spring popped up everywhere in the valley". wn #3 burst out v. erupt or intensify suddenly; "Unrest erupted in the country"; "Tempers flared at the meeting"; "The crowd irrupted into a burst of patriotism". wn