/ˈbɒtəm ||; ˈbɑtəm/noun1 [C] [usu.sing] the lowest part of sth 底部: The house is at the bottom of a hill. 这座房子位于山脚。I think I've got a pen in the bottom of my bag. 我想我的手提包最底下有笔。The sea is so clear that you can see the bottom. 大海清澈见底。
2 [C] the flat surface on the outside of an object, on which it stands 底面: There's a label on the bottom of the box. 箱底有个标签。
3 [sing] the far end of sth 尽头: The bus stop is at the bottom of the road. 公共汽车站在马路尽头。
4 [sing] the lowest position in relation to other people, teams, etc （等级、职位等的）最底层: She started at the bottom and now she's the Managing Director. 她由最底层做起，今天已经是总经理。
5 [C] the part of your body that you sit on 臀部；屁股: He fell over and landed on his bottom. 他摔倒时屁股着地。 ☞picture at body 见body插图
6 bottoms [pl] the lower part of a piece of clothing that is in two parts 两件式服装的下身: pyjama bottoms 睡裤track suit bottoms 运动裤
be at the bottom of sth to be the cause of sth 为…的起因；是…的根由:
I'm sure Molly Potter is at the bottom of all this. 我敢说全部都是莫利˙波特的缘故。 from the (bottom of your) heart→
HEART to find out the real cause of sth 弄清真相；摸清底细