blindage

from The Century Dictionary.

• noun Milit., a blind; a screen made of timber and earth, used to protect men in a trench or covered way; also, a mantelet.
• noun A hood so arranged that it can be made to cover the eyes of a horse if he essays to run away.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Mil.) A cover or protection for an advanced trench or approach, formed of fascines and earth supported by a framework.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun military A cover or protection for an advanced trench or approach, formed of fascines and earth supported by a framework.