势不可当

shì bù kě dāng · HSK 7

impossible to resist

🌊 势 momentum + 不可 cannot-be + 当 blocked = a force nothing can block

势 is force or momentum, 不可 means cannot-be, and 当 here means to block or withstand. Put together: momentum so strong nothing can block it. Like a flood wall giving way, the 当 (blocking) simply fails.

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'.

可 — mouth 口 + breath marker 丁 (modified)
可 originally depicted a mouth (口) with a curved stroke suggesting exhaled breath or speech, conveying approval or assent. From this came the meaning 'to permit' or 'can,' as granting permission was expressed verbally. Today it broadly means 'may,' 'can,' or 'approve.'

当 — small ⺌ + crown 冖 + hand 彐 (simplified from 當: 尚 + 田)
Originally written 當, combining 田 'field' with 尚 as a phonetic. The early sense was 'to match' or 'face' a field of equal value, extended to 'correspond to', 'ought to', and 'serve as'. The simplified form 当 streamlines the upper 尚 component.

More Chinese words · How Chinese works