绷
běng · HSK 7
to stretch
🪢 sounds like bung — bung a cord tight to stretch it taut
Thread 纟 on the left hints at string or fabric. The right side 朋 (friend) gives the sound. Think of bunging a rope tight between two posts — pulled taut and bound firm.
绷 — silk radical 纟 + 朋 (bēng phonetic)
A semantic-phonetic compound. The silk radical 纟 indicates the meaning, originally referring to binding or wrapping with cords or cloth. The component 朋 supplies the sound. From 'tie tightly' the meaning extended to 'stretch taut,' 'strain,' and colloquially 'to hold back' or 'put on a stiff face.'