Bible Dictionaries
Circumvallation

Webster's Dictionary

(1):

(n.) The act of surrounding with a wall or rampart.

(2):

(n.) A line of field works made around a besieged place and the besieging army, to protect the camp of the besiegers against the attack of an enemy from without.

Bibliography Information
Webster, Noah. Entry for 'Circumvallation'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​c/circumvallation.html. 1828.