na-adjective, noun
Describes a state of giving up on caution or consequences, often from frustration or despair. Common in the phrase 捨て鉢になる.
彼は失恋して捨て鉢になっている。
He's become reckless after being dumped.
捨て鉢な態度をとるのはやめなさい。
Stop acting so desperate.
自暴自棄 is a stronger, more formal term for complete self-abandonment and despair, while 捨て鉢 is more colloquial and implies a reckless, 'throw caution to the wind' attitude.
やけくそ is a very casual, almost slangy term for acting out of desperation or frustration, similar to 捨て鉢 but with a rougher nuance.
Compound of 捨て (throwing away) and 鉢 (bowl), literally 'throwing away the bowl'. The exact origin is uncertain, but it likely refers to a monk abandoning his alms bowl in despair, symbolizing giving up on one's livelihood or discipline.