coulisse
noun
cou·lisse kü-ˈlēs 
-ˈlis
1
a
: a side scene of a stage
also : the space between the side scenes
b
: a backstage area
c
: hallway
2
: a piece of timber having a groove in which something glides
Example Sentences
Recent Examples on the Web Crafted from handmade Japanese paper and bamboo in three colorways, each with a different configuration, including a T-shape and a single panel, the collection is named for coulisses — painted pieces of scenery that give a stage set its dimension. 
New York Times, 11 Oct. 2019
New York Times, 11 Oct. 2019 Word History
Etymology
French, from Old French coulice portcullis, from feminine of coleïz flowing, sliding, from couler
First Known Use
1786, in the meaning defined at sense 1a