allergist

The word 'allergist' is a modern medical formation. Its core component, 'allergy', was coined in 1906 by Austrian pediatrician Clemens von Pirquet from the Greek elements 'allos' (meaning 'other' or 'different') and 'ergon' (meaning 'work' or 'activity'), to describe a hypersensitive or 'altered reaction' of the immune system. The suffix '-ist', of ultimate Greek origin via Latin, is a prolific agent-noun suffix in English, appended to 'allergy' to create a term for the specialist dealing with this condition. Thus, an allergist is literally 'a specialist in altered bodily reactions.'

Structure: allerg (allergy) + ist (person who specializes) - allerg: A morpheme derived from the German medical term 'Allergie', itself from Greek 'allos' (other, different) and 'ergon' (work, activity). In this compound, it functions as the base denoting the condition of allergy. - ist: A suffix of Greek origin (via Latin '-ista'), denoting a person who practices or is concerned with something, or a specialist in a field.