The Collaborative International Dictionary of English v.0.48:

Delimitation \De*lim`i*ta"tion\, n. [L. delimitatio: cf. F.
   d['e]limitation.]
   The act or process of fixing limits or boundaries;
   limitation. --Gladstone.
   [1913 Webster]

WordNet (r) 3.0 (2006):

delimitation
    n 1: a line that indicates a boundary [syn: boundary line,
         border, borderline, delimitation, mete]

Moby Thesaurus II by Grady Ward, 1.0:

55 Moby Thesaurus words for "delimitation":
   border line, bound, boundary, boundary condition, boundary line,
   bounding, bourn, break boundary, breakoff point, ceiling,
   circling-in, circumscribing, circumscription, compass, confine,
   cutoff, cutoff point, deadline, definition, demarcation,
   determinant, determination, division line, encincture, end,
   extremity, finish, floor, frontier, hedge, high-water mark,
   inclusion-exclusion, interface, limen, limit, limitation,
   limiting factor, line, line of demarcation, low-water mark,
   lower limit, march, mark, mete, specification, start,
   starting line, starting point, target date, term, terminal date,
   terminus, threshold, time allotment, upper limit