To collapse or fall into or as if into a faint.倾覆或倒下,状如晕倒
柯林斯高阶英汉双解学习词典释义
N-COUNT
(船的)龙骨
The keel of a boat is the long, specially shaped piece of wood or steel along the bottom of it.
PHRASE
平稳进行;顺顺当当
If you say that someone or something is on an even keel, you mean that they are working or progressing smoothly and steadily, without any sudden changes.