The phrase "spring out" is used to describe a sudden and energetic movement. There are a number of synonyms for this term that can be used to describe this type of motion. Some of the most common options include "burst out," "leap out," "pop out," "jump out," and "flare out." Each of these phrases captures a different aspect of the sudden and dynamic movement that is associated with springing out of a place or into action. Whether you are describing an athlete jumping from the starting line or a wild animal leaping out of the brush, there is a synonym for "spring out" that can help you convey this type of energy and excitement.