Source : Webster's Revised Unabridged Dictionary (1913)

Behead \Be*head"\, v. t. [imp. & p. p. {Beheaded}; p. pr. & vb.
   n. {Beheading}.] [OE. bihefden, AS. behe['a]fdian; pref. be-
   + he['a]fod head. See {Head}.]
   To sever the head from; to take off the head of.

Source : WordNet®

beheaded
     adj : having had the head cut off; "the beheaded prisoners" [syn:
           {decapitated}]