Not smiling — and said of a person's face or manner in a way that suggests it is their normal state, not a passing mood. If someone is unsmiling, they look serious, cold, and not friendly. We use it most often about a face, a look, or a person watching or waiting: an unsmiling guard, an unsmiling face at the door, unsmiling officials sitting in a row. It is usually a description from outside — you see the person, you cannot tell what they feel, and the not-smiling is what you notice. It carries a small chill. It does not mean angry, and it does not mean sad; it means closed. Writers like it because it is quiet: instead of saying 'he was cold to me', you can say 'he shook my hand, unsmiling'. It is a little more literary than everyday speech. In normal talk we more often say 'he didn't smile' or 'he looked serious'. Note also that unsmiling can describe one moment ('she listened, unsmiling') or a whole personality ('an unsmiling man who never joined the jokes'), and the second use is stronger — it says something about who the person is.

面無笑容的、不苟言笑的（若指個性，常說「板著臉」「一臉嚴肅」）