The Collaborative International Dictionary
Contramure
Contramure \Con"tra*mure\, n. [Cf. Countermure.] (fort.)
An outer wall. [Obs.]
--Chambers.
Wikipedia
Contramure
In military fortification, a contramure, or countermure, is a wall raised behind another, to supply its place when breached or destroyed.
The term was also used to refer to an outer wall, built around the wall of a city.