dehydrate
verb [ I or T ] uk/ˌdiː.haɪˈdreɪt/ us/ˌdiː.haɪˈdreɪt/
去除（…的）水分，（使）脱水
to lose water, or to cause water to be lost from something, especially from a person's body
Air travel dehydrates the body. 航空旅行会使人体脱水。
You'll dehydrate very quickly in this heat if you don't drink lots of water. 天这么热，不大量喝水身体很快就会脱水。