'allergic' originates from the Greek word 'allergia,' where 'allos' meant 'other' and 'ergon' meant 'work.'

'allergia' transformed into the German word 'Allergie,' and eventually became the modern English word 'allergy' and its adjective form 'allergic.'

Initially, it meant 'a different reaction,' but over time it evolved into its current meaning of 'having an allergy.'