burst out in WordNet English dictionary

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