The Collaborative International Dictionary of English v.0.48:
left-winger \left-winger\ n. 1. a person who belongs to the political left. Syn: socialist, collectivist, leftist. [WordNet 1.5]WordNet (r) 3.0 (2006):
left-winger n 1: a person who belongs to the political left [syn: collectivist, leftist, left-winger]