The Collaborative International Dictionary of English v.0.48:
5-hitter \5-hitter\ n. 1. a game in which a pitcher allows the opposing team 5 hits. Syn: five-hitter [WordNet 1.5]WordNet (r) 3.0 (2006):
5-hitter n 1: a game in which a pitcher allows the opposing team 5 hits [syn: five-hitter, 5-hitter]