cannonball

Etymology

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

noun

1. (military, weaponry)
   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.
2. (diving) 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.
   The New Yorker, 30 August 2004, p.40
   The cannonball could be called the S.U.V. of the pool — oversized, brash, hormonally hardwired.
3. (slang, figurative) Something that moves fast, especially a fast train.
   Meetings of the model train club always begin with the song "Wabash Cannonball".
4. (tennis) A served ball that travels with great speed and describes little or no arc in flight.

verb

1. (intransitive) To jump or dive into water, performing a cannonball landing.
   He cannonballed into the pool, drenching us all.
2. (intransitive) To career; to move rapidly.
   The car cannonballed past.