noun or participle which takes 'suru', intransitive verb
feel sudden remorse; repent deeply
Rare literary expression for a sudden, profound change of heart and regret. Often used in formal or classical contexts.
彼は自分の過ちに翻然悔悟し、深く反省した。
He felt sudden remorse for his mistake and deeply reflected on it.
A Sino-Japanese compound (四字熟語) combining 翻然 (suddenly) and 悔悟 (repentance). The exact historical derivation is uncertain, but it follows classical Chinese literary patterns.