arrière-voussure
noun
arrière-vous·sure
-ˌvüˈsu̇(ə)r
plural -s
1
: an inner or rear arch in a thick wall that carries the inner part of that wall
especially : such an arch over a door or window frame
2
: a relieving arch behind the face of a wall
Word History
Etymology
French, literally, rear arching, from arrière rear, behind + voussure arching, bend of an arch, from (assumed) Vulgar Latin volsura, from volsus (past participle of Latin volvere to roll) + Latin -ura -ure