The Collaborative International Dictionary of English v.0.48:
Tormenter \Tor*ment"er\, n. 1. One who, or that which, torments; a tormentor. [1913 Webster] 2. An executioner. [Obs.] --Chaucer. [1913 Webster]WordNet (r) 3.0 (2006):
tormenter n 1: someone who torments [syn: tormentor, tormenter, persecutor] 2: a flat at each side of the stage to prevent the audience from seeing into the wings [syn: tormenter, tormentor, teaser]