肃 sù to pay respects
to pay respects; solemn; reverent
How it came to be
A hand holds a brush over a deep pit or a piece of sewing: careful work, because a mistake cannot be undone. That care, shown to a person, is paying respect.
How it is used
- 肃 is bound and formal, meaning solemn or reverent, and mainly survives in one common word.
- 严肃 yánsù means 'serious/solemn' about a tone, expression, or attitude: 他表情很严肃 (tā biǎoqíng hěn yánsù) - his expression is very serious.
- 严肃 is stronger and more formal than 认真 rènzhēn (serious/conscientious about doing something well) - 严肃 describes gravity or sternness, not diligence.