1. a round metal ball fired from a cannon
Usage: historical
2. a jump into water with knees pulled up to the chest
Usage: informal

1. to move very fast and forcefully
Usage: informal
2. to jump into water in a cannonball position
Usage: informal

Examples

• The old fort displayed rusty cannonballs from the Civil War.
• He did a perfect cannonball into the swimming pool.
• The kids took turns doing cannonballs off the diving board.
• The truck cannonballed down the highway at dangerous speeds.
• She cannonballed into the lake with a huge splash.
• The museum had a collection of historic cannonballs and weapons.
• Don’t cannonball through the hallways at school.