The Collaborative International Dictionary of English v.0.48:

Vaimure \Vai"mure\, n.
   An outer, or exterior, wall. See Vauntmure. [Obs.]
   --Hakluyt.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Vauntmure \Vaunt"mure`\, n. [F. avant-mur. See Vanguard, and
   Mure.] (Fort.)
   A false wall; a work raised in front of the main wall.
   [Written also vaimure, and vamure.] --Camden.
   [1913 Webster]