backcloth
noun
back·cloth ˈbak-ˌklȯth 
chiefly British
: backdrop
Example Sentences
Recent Examples on the Web Morris’s giant vertical beam traverses back and forth across the front of the stage, shining on the backcloth and the dancers in its path. 
Melissa Harris, The New York Review of Books, 11 Jan. 2020
Melissa Harris, The New York Review of Books, 11 Jan. 2020 Word History
First Known Use
1874, in the meaning defined above