left field is a noun meaning "the piece of ground in the outfield on the catcher's left". It carries 2 recorded senses.
the fielding position of the player on a baseball team who is expected to field balls in the left third of the outfield (looking from home plate)
Definitions, synonyms and semantic relations for left field come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.