noun
satisfied face; look of understanding
Describes a facial expression showing that someone has understood and accepted an explanation or situation. Often used when a person's doubts are resolved.
彼は説明を聞いて納得顔になった。
After hearing the explanation, he had a satisfied look on his face.
先生の話に、生徒たちは納得顔でうなずいた。
The students nodded with looks of understanding at the teacher's story.
満足顔 is a satisfied face in general, often from pleasure or contentment, while 納得顔 emphasizes satisfaction from understanding or being convinced.
Compound of 納得 (understanding, acceptance) and 顔 (face).