- A rack (sometimes called a triangle) is the equipment used to place billiard balls in their starting positions at the beginning of a pocket billiards game.
- Rack may also be used as a verb to describe the act of setting billiard balls in their starting positions (e.g. “to rack the balls”), or as a noun to describe a set of balls that are in their starting positions (e.g. “a rack of balls”, more often called a pack or a pyramid in British English).