Noviro
严肃
HSK5
Simplified 严肃
Traditional 嚴肅
Pinyin yán sù
Definition (of an atmosphere etc.) solemn; grave; serious; (of a manner etc.) earnest; severe; exacting; to strictly enforce
这么严肃放松
Bié zhème yánsù, fàngsōng diǎn
Don't be so serious, relax a bit