The Collaborative International Dictionary of English v.0.48:
Attempter \At*tempt"er\ (?; 215), n. 1. One who attempts; one who essays anything. [1913 Webster] 2. An assailant; also, a temper. [Obs.] [1913 Webster]WordNet (r) 3.0 (2006):
attempter n 1: one who tries [syn: trier, attempter, essayer]