glacis
/ˈglæsɪs/noun
(复同单 /-sIz/)
1- a bank sloping down from a fort which exposes attackers to the defenders' missiles（堡垒前的）斜堤, 斜坡。
1.1
- （亦作glacis plate）a sloping piece of armour plate protecting part of a vehicle（对车辆起保护作用的）斜装甲板。
词源
late 17th cent.: from French, from Old French glacier 'to slip', from glace 'ice', based on Latin glacies.