1. (挂在舞台后部的)彩画幕布,背景幕布
A backdrop is a large piece of cloth, often with scenery painted on it, that is hung at the back of a stage while a play is being performed.
2. (实物或景象的)背景,衬托
The backdrop to an object or a scene is what you see behind it.
e.g. Leeds Castle will provide a dramatic backdrop to a fireworks display next Saturday...
利兹堡将为下周六的烟花燃放提供美妙的背景衬托。
e.g. Light colours provide an effective backdrop for pictures or a mirror.
浅色是挂放图画或镜子很有效果的衬托。
3. (事件的)背景
The backdrop to an event is the general situation in which it happens.
e.g. The election will take place against a backdrop of increasing instability.
选举将在愈加动荡不安的局势下举行。