'nonapplicability' originates from Modern English, specifically formed from the prefix 'non-' and the noun 'applicability', where 'non-' meant 'not' and 'applicability' meant 'the quality of being applicable'.

'applicability' derives from Late Latin/Latin elements: Latin 'applicare' ('to apply, to attach') produced Medieval/Modern forms such as Old French 'applicable'/'applicabilite' and Middle English 'applicable'/'applicability'; the negative prefix 'non-' (from Latin 'non') was later attached to create 'nonapplicability' in Modern English usage.

Initially related to the Latin idea of 'attaching' or 'applying' (from 'applicare'), the sense evolved to mean 'suitability or relevance' (applicability); adding 'non-' changed the meaning to 'the lack or absence of that suitability/relevance'.