This word is acceptable for play in the UK dictionary that is being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A cannonball.

n. A stone used for the shot of a catapult or cannon. Before the invention of iron balls, stones were commonly used as projectiles.

n. A flint prepared for insertion in the lock of a gun. See flint-lock.

"The brute landed with the force and grace of an enormous gunstone, square on the roof of the small wagon."