1. Sports
a. A game played by two teams of 11 players each on a rectangular, 100-yard-long field with goal lines and goalposts at either end, the object being to gain possession of a ball and advance it in running or passing plays across the opponent's goal line or kick it through the air between the opponent's goalposts.
b. The inflated oval ball used in this game.
2. Chiefly British
a. Rugby.
b. Soccer.
c. The ball used in Rugby or soccer.
3. Informal A problem or issue that is discussed among groups or persons without being settled: The issue of tax reform became a political football.