The Collaborative International Dictionary of English v.0.48:

Hallucinator \Hal*lu"ci*na`tor\
   (h[a^]l*l[=u]"s[i^]*n[=a]`t[~e]r), n. [L.]
   One whose judgment and acts are affected by hallucinations;
   one who errs on account of his hallucinations. --N. Brit.
   Rev.
   [1913 Webster]