Carom came into use in the 1860s and is a shortening of carambola , which was earlier used to describe the red object ball used in many billiards games. Carom generally refers to any type of strike and rebound, off a rail or ball, but may also be used as short for a carom shot in which a point is scored in carom billiards games by careening the cue ball into the two object balls. Also called a cannon in British terminology.