greenroom

名词 greenroom:

1. a backstage room in a theater where performers rest or have visitors

green.room

n.（名词）
A waiting room or lounge in a theater or concert hall for the use of performers when they are off-stage.
演员休息室：剧场或音乐厅里后台供演员休息的房间或休息厅

来源：
[So called because such rooms were originally painted green]
[因原先剧场演员休息室被刷成绿色，故得名]