'nonapplicable' originates from the combination of the negative prefix 'non-' (from Latin 'non', meaning 'not') and the adjective 'applicable' (from Latin 'applicabilis', from 'applicare', meaning 'to apply' or 'attach').

'applicabilis' changed into Old French and then into Middle English as 'applicable', and in Modern English the negative prefix 'non-' was attached to form the compound 'nonapplicable'.

Initially the components meant 'not' and 'able to be applied'; over time the compound came to be used to mean 'not able or not relevant to be applied', i.e. 'not applicable'.