Source : Webster's Revised Unabridged Dictionary (1913)

Exterminator \Ex*ter"mi*na`tor\, n. [L.]
   One who, or that which, exterminates. --Buckle.

Source : WordNet®

exterminator
     n : someone who exterminates (especially someone whose
         occupation is the extermination of troublesome rodents
         and insects) [syn: {terminator}, {eradicator}]