NOUN (2)

1. a capsule filled with water-soluble dye used as a projectile in playing the game of paintball;

2. a game that simulates military combat; players on one team try to eliminate players on the opposing team by shooting capsules of paint at them;

WordNet (r) 3.0 (2006):

paintball
    n 1: a capsule filled with water-soluble dye used as a
         projectile in playing the game of paintball
    2: a game that simulates military combat; players on one team
       try to eliminate players on the opposing team by shooting
       capsules of paint at them