The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

            By the bare scalp of Robin Hodd's fat friar,
            This fellow were a king for our wild faction!
                                                  --Shak.
      [1913 Webster]

   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.
      [1913 Webster]

   3. Fig.: The top; the summit. --Macaulay.
      [1913 Webster]

   Scalp lock, a long tuft of hair left on the crown of the
      head by the warriors of some tribes of American Indians.
      [1913 Webster]

WordNet (r) 3.0 (2006):

scalp lock
    n 1: a long tuft of hair left on top of the shaven head