Dictionary
con•tra•val•la•tion
Pronunciation: (kon"tru-vu-lā'shun), [key]—
n. Fort.
a more or less continuous chain of redoubts and breastworks raised by besiegers outside the line of circumvallation of a besieged place to protect the besiegers from attacks from the outside, as by a relieving force.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.