"底部" 在英语中通常称作 "bottom". 这个词来源于古英语中的 "botm"，意思是 "下面的部分" 或 "最低点".

例句：

The fish swims near the bottom of the lake. (这条鱼游在湖底附近。)

I left my pencil at the bottom of my backpack. (我把铅笔放在背包底部。)

She reached the bottom of the stairs and stopped to catch her breath. (她走到楼梯底部，停下来喘气。)