na-adjective
sorry-looking; apologetic; remorseful
Describes a person's expression, attitude, or manner that shows they feel sorry or guilty. Often used when someone looks like they want to apologize.
彼は済まなそうな顔で謝った。
He apologized with a sorry look on his face.
遅刻して、すまなそうに頭を下げた。
Being late, he bowed his head apologetically.