na-adjective, noun
indomitable perseverance; invincible fortitude
A yojijukugo describing unwavering determination and endurance in the face of hardship. Often used in formal or literary contexts to praise steadfast character.
彼は堅忍不抜の精神で難局を乗り越えた。
He overcame the crisis with indomitable perseverance.
成功には堅忍不抜の努力が必要だ。
Success requires invincible fortitude.