[bә:m]
n.
城墙与外濠间之狭道, 崖径

Berm \Berm\ Berme \Berme\, n. [F. berme, of German origin; cf.
G. brame, br["a]me, border, akin to E. brim.]
1. (Fort.) A narrow shelf or path between the bottom of a
parapet and the ditch.

2. (Engineering) A ledge at the bottom of a bank or cutting,
to catch earth that may roll down the slope, or to
strengthen the bank.