Source : Webster's Revised Unabridged Dictionary (1913)

Determinist \De*ter"min*ist\, n. (Metaph.)
   One who believes in determinism. Also adj.; as, determinist
   theories.

Source : WordNet®

determinist
     n : anyone who submits to the belief that they are powerless to
         change their destiny [syn: {fatalist}, {predestinarian},
         {predestinationist}]