base on balls is a noun meaning "(baseball) an advance to first base by a batter who receives four balls". It carries one recorded sense.
(baseball) an advance to first base by a batter who receives four balls
“he worked the pitcher for a base on balls”
baseball
Definitions, synonyms and semantic relations for base on balls come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.