The Collaborative International Dictionary of English v.0.48:
Alleviator \Al*le"vi*a`tor\, n. One who, or that which, alleviates. [1913 Webster]WordNet (r) 3.0 (2006):
alleviator n 1: a therapist who makes suffering more endurable 2: remedy that alleviates pain without curing [syn: palliative, alleviant, alleviator]