1. any game played with a ball, esp. baseball or softball.
2. Informal. a situation and all its attendant circumstances: Having a new administration in power changes the entire ball game at city hall. Cf. new ball game .
3. Archaeol. a ceremonial game of both ritual and sporting significance, played by teams on a ball court in Mesoamerican cultures from the Preclassic period to the Spanish conquest.
Also, ballgame .
[ 1840-50, Amer. ]