'nonatopy' originates from Modern English, formed by the negative prefix 'non-' (from Latin 'non', meaning 'not') combined with 'atopy' (from Greek 'atopia'/'atopos', meaning 'strangeness' or 'out of place').

'nonatopy' was formed in modern medical English by attaching the prefix 'non-' to 'atopy'. The term 'atopy' entered English via Modern Latin/medical usage from Greek 'atopia' (from 'atopos'), which meant 'out of place' or 'strange'.

Originally Greek 'atopos' meant 'out of place' or 'strange'; in medical usage 'atopy' came to mean a predisposition to allergic hypersensitivity, and 'nonatopy' now denotes the absence of that predisposition.