1720-30; Latinization of Spanishdemarcación (in linea de demarcación line of demarcation, dividing the world between Spain and Portugal) derivative of demarcar to mark out the bounds of, equivalent to de-de- + marcar < Italianmarcare < Germanic; see mark1, -ation
c.1752, from Sp. linea de demarcacion, or Port. linha de demarcaçao, line laid down by the Pope, May 4, 1493, dividing the New World between Spain and Portugal on a line 100 leagues west of the Cape Verde Islands. Applied from 1801 to other lines dividing regions.