godan verb (-su), expression
look gloomy; cloud one's face
Describes a facial expression becoming sad, worried, or troubled, often in reaction to bad news or a negative thought.
See also: 曇らす
その知らせを聞いて、彼は顔を曇らせた。
Hearing the news, his face clouded over.
急
Suddenly looking gloomy, he seemed lost in thought.