staid
/steɪd; sted/ adj
(sometimes derog 有时作贬义) (of people, their appearance, behaviour, tastes, etc) serious, dull and old-fashioned; conservative （指人、 外表、 行为、 爱好等）古板的, 保守的, 一本正经的
I was surprisedto see him at the jazz club; I always thought of him as a rather staid old gentleman. 我在爵士舞俱乐部见到他时很感意外, 我还一直以为他是个挺古板的绅士呢.