verb (v)

• give sudden release to an expression(verb.communication)

  Example:
  We burst out laughing.
  'I hate you,' she burst out.
  

  source: wordnet30
• appear suddenly(verb.change)

  Synonym:
  pop out
  

  source: wordnet30
• erupt or intensify suddenly(verb.change)

  Synonym:
  break open, erupt, flare, flare up, irrupt
  

  source: wordnet30