allergy allergist • allerion · · · Info · Definitions · Synonyms · Characters · · allergy · · Text Latin · · Script 7 · · Length Definitions · · · (noun) hypersensitivity reaction to a particular allergen; symptoms can vary greatly in intensity. Synonyms: allergic reaction. · · Noun Definition 1 Synonyms · · · allergic reaction · · Synonym 1 Characters · · a latin small letter a U+0061 e latin small letter e U+0065 g latin small letter g U+0067 l latin small letter l U+006C r latin small letter r U+0072 y latin small letter y U+0079