an explanation, excuse, or justification for one's actions — offering a defense or rationale.
遅刻した理由を弁解したが、納得はされなかった。
He offered an excuse for being late, but it wasn't accepted.
弁解の余地はなく、謝罪するしかなかった。
There was no room for excuse; he had no choice but to apologize.
彼女は自分の行動について詳しく弁解した。
She gave a detailed explanation of her actions.