1. 倾覆：keel boat 内河运货船 | keel over 倾覆 | keel 龙骨

2. 船底朝天：keel metacenter 稳心至龙骨距离 | keel over 船底朝天 | keel piece 龙骨框底部

3. 昏倒：know a lot if people in high place 认识达官显贵 | keel over 昏倒 | keep my finger cross 祈求好运

4. 倒下：扫地 sweep the floor | 倒下 fall over; fall down; collapse; drop; fall ; keel over | 睡觉 to sleep; go to bed

1. （因疲劳或生病而）倒下，瘫倒
If someone keels over, they collapse because they are tired or ill.

e.g. He then keeled over and fell flat on his back.
然后，他便仰天倒下了。

verb

1. turn over and fall

e.g. the man had a heart attack and keeled over