third base is a noun meaning "the base that must be touched third by a base runner in baseball". It carries 2 recorded senses.
the fielding position of the player on a baseball team who is stationed near the third of the bases in the infield (counting counterclockwise from home plate)
“he is playing third”
Definitions, synonyms and semantic relations for third base come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.