Burst out Definition 1 of 3Pro Tip 1/3Forceful Expression Used to describe a sudden and intense occurrence often linked with strong emotions or reactions. He burst out in a fit of anger. Pro Tip 2/3Uncontainable Outburst Implies something can no longer be controlled or contained and comes out all at once. The crowd burst out in cheers after the winning goal. Pro Tip 3/3Visual Imagery Often conjures a vivid image of something breaking or shattering suddenly. Sunlight burst out from behind the clouds.