'nonallergic' originates from Modern English, specifically formed from the negative prefix 'non-' and the adjective 'allergic', where 'non-' meant 'not' and 'allergic' comes from 'allergy' (coined from Greek elements).

'non-' (a productive English prefix from Latin 'non' meaning 'not') was attached to 'allergic' (from 'allergy', a term introduced in the early 20th century from German 'Allergie', itself from Greek 'allos' + 'ergon'), producing 'nonallergic' in modern medical usage.

Initially, the elements meant 'not' + (related to) 'allergy'; over time the combined form has been used specifically to label conditions or reactions that are not caused by allergic mechanisms, a usage that has remained consistent.