无不
wúbù · HSK 7
without exception
无 (without) + 不 (not) = without not = nothing fails to happen = invariably
Double negative stacked: 无 means there-is-no and 不 means not, so 无不 literally reads no-not. Two negatives cancel into a strong positive: every single case applies, without exception.
无 — top 一 + 林-like middle + fire radical 灬 below
Originally a pictograph of a person dancing while holding ornaments or tassels, meaning 'to dance' — the ancestor of 舞. It was borrowed phonetically to write the negative 'not have / without,' and the dance meaning was reassigned to 舞 with an added foot element. The simplified form 无 comes from an ancient variant.
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'.