A section of Hadrian's Wall.
Hadrian's Wall definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
stone wall across N England, from Solway Firth to the Tyne: built ( 122-128) by Hadrian to protect Roman Britain from N tribes: 73.5 mi (118.3 km)
Hadrian's Wall definition by American Heritage Dictionary
An ancient Roman wall, 118.3 km (73.5 mi) long, across northern England. Built by the emperor Hadrian c. A.D. 122-126 and extended by Severus a century later, the wall marked the northern defensive boundary of Roman Britain. Fragmentary ruins of the wall remain.