Source : Webster's Revised Unabridged Dictionary (1913)

Decollate \De*col"late\, v. t. [imp. & p. p. {Decollated}; p.
   pr. & vb. n. {Decollating}.] [L. decollatus, p. p. of
   decollare to behead; de- + collum neck.]
   To sever from the neck; to behead; to decapitate.

         The decollated head of St. John the Baptist. --Burke.