1Feeling frustrated, upset, or bitter about a loss, failure, or unfair treatment — the mix of disappointment and irritation felt when things don't go your way.
試合に負けて本当に悔しい。次は絶対勝ちたい。
I'm really frustrated about losing the match. I definitely want to win next time.
あの時言い返せなかったのが悔しくて、今でも思い出す。
I still remember how frustrated I was that I couldn't talk back at the time.
悔しいけど、今回は彼の方が実力が上だった。
It's frustrating to admit, but he was simply better this time.
1点差で負けるなんて、こんなに悔しいことはない。
Losing by just one point is about the most frustrating thing there is.