拥挤的英文是 "crowded".

来源：
这个词来自中世纪拉丁语 "crowdare"，意思是堆积，压挤。

英文例句及中文翻译：

The train was crowded with people during rush hour.
火车在高峰期里充满了人群。
The park was too crowded, so we decided to leave.
公园太拥挤了，所以我们决定离开。
The beach was crowded with sunbathers on the weekend.
沙滩上周末人满为患。