1. (baseball) an advance to first base by a batter who receives four balls; - Example: "he worked the pitcher for a base on balls" [syn: base on balls, walk, pass]
WordNet (r) 3.0 (2006):
base on balls
n 1: (baseball) an advance to first base by a batter who
receives four balls; "he worked the pitcher for a base on
balls" [syn: base on balls, walk, pass]