Glacis

Noun

1. A gentle incline. A gentle sloping landform created by the deposition or erosion of material. A gentle incline in front of a fortification which protects it from cannon fire and exposes attackers to more effective return fire from defenders.
2. A gentle sloping landform created by the deposition or erosion of material.
3. A gentle incline in front of a fortification which protects it from cannon fire and exposes attackers to more effective return fire from defenders.
4. A gentle incline in front of a fortification which protects it from cannon fire and exposes attackers to more effective return fire from defenders.
5. In full glacis plate: the angled armour plate on the front of a tank which protects it from projectiles; also , such a plate protecting an opening (for example, on a ship).