A backcloth is a large piece of cloth, often with scenery or buildings painted on it, that is hung at the back of a stage while a play is being performed.
N-SING
（事件的）背景
The backcloth to an event is the general situation in which it happens.
例句
I'm not impressed by the promise of tax cuts against the backcloth of a public-spending deficit.在公共開支出現赤字的情況下承諾減稅讓我不以為然。