This is the 9932nd most frequent Japanese word.
負ける
"負ける" means "to lose" (in a competition or fight).
The word '負ける' is used here to mean 'to lose', as in losing a competition or a fight.
試合で負けると悔しい気持ちになる。
Losing in a match makes you feel regretful.
In this context, '負ける' metaphorically means that the plan could not succeed or was defeated by circumstances.
雨が降ったために、彼の計画が負けてしまった。
Due to the rain, his plan fell through.
Here, '負ける' implies yielding or succumbing to something, in this case, one's emotions.