demarcation

plural demarcations · alternative demarkation

1. countableuncountableThe act of marking off a boundary or setting a limit, notably by belligerents signing a treaty or ceasefire.
2. countableuncountableA limit thus fixed, in full demarcation line.

   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, […], →OCLC, pages 48–49

3. countableuncountableAny strictly defined separation.

   There is an alleged, in fact somewhat artificial demarcation in the type of work done by members of different trade unions.

   2 more examples

   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, →ISBN, page 7

   Certainly no clear line of demarcation has as yet been drawn between species and sub-species—that is, the forms which in the opinion of some naturalists come very near to, but do not quite arrive at the rank of species; or, again, between sub-species and well-marked varieties, or between lesser varieties and individual differences. These differences blend into each other in an insensible series; and a series impresses the mind with the idea of an actual passage.

   1859, Charles Darwin, On the Origin of Species