cannonball

Meanings

1. A spherical projectile fired from a smoothbore cannon.
2. An explosive-filled hollow iron sphere fused through a hole and intended to explode at a calculated distance rather than explode on impact.
3. The act of jumping (typically into a swimming pool) with the legs bent and the arms wrapped around the knees to create a large splash, mimicking the flight and shape of a cannonball.
4. Something that moves fast, especially a fast train.
5. A served ball that travels with great speed and describes little or no arc in flight.

1. To jump or dive into water, performing a cannonball landing.
2. To career; to move rapidly.

Etymology

From cannon + ball from being a round ball that is fired from a cannon.