GLACISES

Noun

glacises

plural of glacis

Source: Wiktionary

GLACIS

Gla"cis, n. Etym: [F. glacis; -- so named from its smoothness. See Glacier.]

Definition: A gentle slope, or a smooth, gently sloping bank; especially (Fort.), that slope of earth which inclines from the covered way toward the exterior ground or country (see Illust. of Ravelin).

Source: Webster’s Unabridged Dictionary 1913 Edition