A type of projectile for muzzle-loading artillery, consisting of two balls or half-balls connected by a bar or chain. Widely used in naval warfare of the 18th and 19th centuries to destroy the masts and rigging of enemy ships.

Until I researched this wu I believed chain shot were fired from two separate cannon, requiring perfect synchronization by the gunners to avoid carnage around the gun crew. How stupid am I?

In fact, both bar and chain shot are fired from a single gun, and depend on centrifugal force imparted by nonuniform friction inside the barrel to separate the shot and cut its characteristic swath.