Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
5-hitter is a noun meaning "a game in which a pitcher allows the opposing team 5 hits". It carries one recorded sense.
a game in which a pitcher allows the opposing team 5 hits
Definitions, synonyms and semantic relations for 5-hitter come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.