The Collaborative International Dictionary of English v.0.48:
Leveler \Lev"el*er\ (-[~e]r), n. [Written also leveller.] 1. One who, or that which, levels. [1913 Webster] 2. One who would remove social inequalities or distinctions; a socialist. [1913 Webster]WordNet (r) 3.0 (2006):
leveler n 1: a radical who advocates the abolition of social distinctions [syn: leveler, leveller]