Source : Webster's Revised Unabridged Dictionary (1913)

Scalp \Scalp\, n. [Perhaps akin to D. schelp shell. Cf.
   {Scallop}.]
   1. That part of the integument of the head which is usually
      covered with hair.

            By the bare scalp of Robin Hodd's fat friar, This
            fellow were a king for our wild faction! --Shak.

   2. A part of the skin of the head, with the hair attached,
      cut or torn off from an enemy by the Indian warriors of
      North America, as a token of victory.

   3. Fig.: The top; the summit. --Macaulay.

   {Scalp lock}, a long tuft of hair left on the crown of the
      head by the warriors of some tribes of American Indians.

Source : WordNet®

scalp lock
     n : a long tuft of hair left on top of the shaven head