Squash

Squash is a high-speed racquet sport played by two players (or in doubles 4 players on court at a time) in a four-walled court with a small, hollow rubber ball. Squash is recognized by the IOC and remains in contention for incorporation in a future Olympic programme.

The game was formerly called squash racquets, a reference to the “squashable” soft ball used in the game (compared with the fatter ball used in its parent game racquets

Reference: Wikipedia Squash