The Collaborative International Dictionary of English v.0.48:

Embattail \Em*bat"tail\, v. t. [See Embattle.]
   To furnish with battlements; to fortify as with battlements.
   [Archaic]
   [1913 Webster]

         To embattail and to wall about thy cause
         With iron-worded proof.                  --Tennyson.
   [1913 Webster]