万人空巷的英文：
[Literal Meaning]
ten thousand/people/empty/alley
Everyone comes out and the alleys are all empty.

[解释]
万人：形容人数极多。指家家户户的人都从巷子里出来了。多形容庆祝、欢迎等盛况。

[Explanation]
to welcome somebody or celebrate some event

[例子]
《阿凡达》刚一上映，小镇里万人空巷，都涌向了电影院。

[Example]
Once Avatar was on, everyone comes out and the alleys are all empty in the small town and swamped into cinemas.