Definition of "demarcation"

demarcation

/ˌdɛmɑːˈkeɪʃən/

noun
countable and uncountable, plural demarcations
1. The act of marking off a boundary or setting a limit, notably by belligerents signing a treaty or ceasefire.
2. A limit thus fixed, in full demarcation line.
  Quotations
  About sunset, he was leaning on the remains of an old wall, which had once probably surrounded a Roman encampment, and now served as a line of demarcation between two villages, as jealous of each other's claims as near neighbours usually are.
  1831, L[etitia] E[lizabeth] L[andon], Romance and Reality. […], volume III, London: Henry Colburn and Richard Bentley, […], pages 48–49
3. Any strictly defined separation.
  Quotations
  In the sea there is no demarcation between the hunter and the hunted, as there is on the African plains.
  1983, Richard Ellis, The Book of Sharks, Knopf, page 7