pog (n.)

disc used in playing a game said to have originated in Hawaii and popular in U.S. during the mid-1990s; said to be from the name of a brand of juice-drink made in Hawaii since about 1971, the milk caps from the bottles of it being used to play the game originally. The juice-drink name is said to be an acronym from passionfruit, orange, and guava, the ingredients of the drink.