If you call someone weak-kneed, you are saying they have no courage and cannot stand firm when it is hard. The picture behind the word is a body: when a person is very afraid, their knees feel soft and shaky, and they cannot stand up straight. So a weak-kneed person gives in — they agree with whoever spoke last, they back down when someone pushes them, they will not say the difficult thing.

If you call someone weak-kneed如果你說某人weak-kneed，you are saying they have no courage就是說他沒有勇氣，and cannot stand firm when it is hard局面艱難時站不穩立場。The picture behind the word is a body這個字背後的畫面跟身體有關：when a person is very afraid當一個人非常害怕時，their knees feel soft and shaky膝蓋會軟掉、發抖，and they cannot stand up straight沒辦法站直。So a weak-kneed person gives in所以一個weak-kneed的人會讓步——they agree with whoever spoke last誰最後講話他就附和誰，they back down when someone pushes them被人一逼就退縮，they will not say the difficult thing不敢說出困難的真話。

It is used most often about politicians, bosses, governments and committees: a weak-kneed response, a weak-kneed apology, weak-kneed leaders. It is always an insult, and quite a strong one, though it is a slightly old-fashioned and bookish insult rather than a rude one — you meet it more in newspapers and speeches than in daily chat.

It is used most often about politicians, bosses, governments and committees最常用在政治人物、老闆、政府和委員會身上：a weak-kneed response, a weak-kneed apology, weak-kneed leaders像weak-kneed response（軟弱的回應）、weak-kneed apology（軟弱的道歉）、weak-kneed leaders（沒骨氣的領袖）。It is always an insult, and quite a strong one這一定是罵人的話，而且罵得很重，though it is a slightly old-fashioned and bookish insult rather than a rude one不過是有點老派、書面味的罵法，不是粗俗的髒話——you meet it more in newspapers and speeches than in daily chat比較常出現在報紙和演講裡，而不是日常聊天。

Note that it is about moral courage, not about the body. A weak-kneed man may be big and strong.

Note that it is about moral courage要注意這說的是道德上的勇氣，not about the body跟身體沒有關係。A weak-kneed man may be big and strong一個weak-kneed的人可能長得高大又強壯。

And be careful: the plain phrase 'my knees went weak' usually means fear or shock, and sometimes love, but the hyphenated adjective weak-kneed is only about character.

And be careful但要小心：the plain phrase 'my knees went weak'一般說法「my knees went weak」 usually means fear or shock, and sometimes love通常指害怕或受到驚嚇，有時候也指陷入愛河，but the hyphenated adjective weak-kneed is only about character但加了連字號的形容詞weak-kneed只跟性格有關。