Countermured vs Countermures - What's the difference?

As verbs the difference between countermured and countermures

is that countermured is past tense of countermure while countermures is third-person singular of countermure.

(head)

(countermure)

(en noun)

A wall raised behind another, to supply its place when that is breached or destroyed.

(Knolles)

(countermur)

To fortify with a wall behind another wall.

(Kyd)

(Webster 1913)

(head)

(countermure)