glacis

Từ điển American Heritage Dictionary 4th

gla·cis (glă-sēʹ, glăsʹē, glāʹsĭs)n. pl. glacis
1.
a. A gentle slope; an incline.
b. A slope extending down from a fortification.
2. A neutral area separating conflicting forces. [French, from Old French, from glacer, to slide, from glace, ice, from Vulgar Latin *glacia, from Latin glaciēs. See gel- in Indo-European Roots.]