The Collaborative International Dictionary of English v.0.48:
4-hitter \4-hitter\ n. 1. a game in which a pitcher allows the opposing team 4 hits. Syn: four-hitter [WordNet 1.5]WordNet (r) 3.0 (2006):
4-hitter n 1: a game in which a pitcher allows the opposing team 4 hits [syn: four-hitter, 4-hitter]