expression, noun-modifying (irregular)
exactly the same; identical; perfect
Fixed prenominal expression emphasizing that two things match in every detail, with no difference whatsoever. Often used in literary or emphatic contexts.
彼の描いた絵は本物と寸分違わぬ出来栄えだった。
The painting he made was identical to the real thing in every detail.
二人の意見は寸分違わぬほど一致していた。
Their opinions matched so perfectly that there was not the slightest difference.
Compound of 寸分 (a tiny amount, from 寸 'sun' and 分 'bu', both small units of length) + 違わぬ (negative form of 違う 'to differ'), literally 'not differing by even a sun or bu'.