tradesman's entrance

剑桥词典

the side or back door of a large house , used, especially in the past, by people delivering goods who were not allowed to use the door at the front of the house
（旧时送货用的）后门
I've forgotten my front-door key , so we'll have to use the tradesmen's entrance . 我忘带了前门钥匙，因此我们只好从后门进屋。 返回 tradesman's entrance