'Circumvallation' definitions:
Definition of 'Circumvallation'
From: GCIDE
- Circumvallation \Cir`cum*val*la"tion\, n. (Mil.) (a) The act of surrounding with a wall or rampart. (b) 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. [1913 Webster]