1. 坝;堤
A dam is a wall that is built across a river in order to stop the water flowing and to make a lake.
e.g. ...plans to build a dam on the Danube River.
在多瑙河上建坝的计划
e.g. ...the Aswan Dam.
阿斯旺大坝
2. 在（河）上筑坝
To dam a river means to build a dam across it.
dam在线翻译
e.g. ...plans to dam the nearby Delaware River...
在附近的特拉华河上筑坝的计划
e.g. This reservoir was formed by damming the River Blith.
这个水库是通过在布莱斯河上筑坝形成的。
3. 雌亲;母畜
In the breeding of farm animals, an animal's dam is its mother.
名词水库; 水坝，堰; （牙科用的）橡皮障; 〈比喻〉障碍
及物动词用水坝阻止; 阻塞，抑制