Source : Webster's Revised Unabridged Dictionary (1913)

Demarcate \De*mar"cate\, v. t. [See {Demarcation}.]
   To mark by bounds; to set the limits of; to separate; to
   discriminate. --Wilkinson.

Source : WordNet®

demarcate
     v 1: separate clearly and as if by boundaries
     2: set, mark, or draw the boundaries of something [syn: {delimit},
         {delimitate}]