dour
adjective uk/dʊər/ us/dʊr/
（通常指人的外表或行为）冷峻的，阴沉的，不苟言笑的
(usually of a person's appearance or manner) unfriendly, unhappy, and very serious
The normally dour Mr James was photographed smiling and joking with friends. 平时不苟言笑的詹姆斯先生照片上却与朋友们谈笑风生。
Synonym: morose