The Collaborative International Dictionary of English v.0.48:
Allayer \Al*lay"er\, n. One who, or that which, allays. [1913 Webster]WordNet (r) 3.0 (2006):
allayer n 1: a person who reduces the intensity (e.g., of fears) and calms and pacifies; "a reliever of anxiety"; "an allayer of fears" [syn: reliever, allayer, comforter]