/dee'mahr kay"sheuhn/ , n.
1. the determining and marking off of the boundaries of something.
2. separation by distinct boundaries: line of demarcation.
Also, demarkation .
[ 1720-30; Latinization of Sp demarcación (in linea de demarcación line of demarcation, dividing the world between Spain and Portugal) deriv. of demarcar to mark out the bounds of, equiv. to de- DE- + marcar marcare 1 , -ATION ]