What is the meaning of burst out?

verb

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