素不相识
sù bù xiāng shí · HSK 7
to be total strangers (idiom)
👋🚫 素(usually) + 不(not) + 相(mutually) + 识(know) = never knew each other at all
Literally never-mutually-acquainted: 相识 means to be acquainted, and 素不 negates it as a standing fact, so two people have always been complete strangers.
素 — silk 糸 + sheng 𠂹 (hanging threads)
Originally depicted raw, undyed silk hanging to dry, with the silk radical 糸 below and strands above. From this came the meaning 'plain, unadorned, white,' then extended to 'basic element' or 'plain/simple' in general. The 'vegetarian' sense developed later from the idea of plain, unembellished food.
不 — single pictograph; bird flying upward
Originally a pictograph in oracle bone script, traditionally interpreted as a bird flying up toward the sky and unable to come down, suggesting negation or refusal. Over time it became the standard negation word in Chinese, used before verbs and adjectives to mean 'not'.
识 — speech radical 讠 + 只 zhī (phonetic)
识 is a semantic-phonetic compound. The speech radical 讠 (言) signals meaning related to words or knowing, while 只 hints at the sound. Originally written 識 with 戠, it meant 'to recognize' or 'know'; later it broadened to include knowledge and awareness.