2. the art or process of building such a defense
Webster’s New World College Dictionary, Fourth Edition, compiled by the
editors of Webster’s New World Dictionaries. Copyright © 2010 by Houghton
Mifflin Harcourt. Published by Houghton Mifflin Harcourt. All rights reserved.
Word origin of 'vallation'
< L vallatus,
pp. of vallare,
to protect with a rampart < vallum,