hypersensitivity reaction hypersensitivity • hypersensitization · · · Info · Definitions · Characters · · hypersensitivity reaction · · Text Common · · Latin · · Scripts 25 · · Length 10 · · Syllables Definitions · · · (noun) an inappropriate and excessive reaction to an allergen (as pollen or dust or animal hair or certain foods); severity ranges from mild allergy to severe systemic reactions leading to anaphylactic shock. Synonyms: hypersensitivity reaction. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 c latin small letter c U+0063 e latin small letter e U+0065 h latin small letter h U+0068 i latin small letter i U+0069 n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074 v latin small letter v U+0076 y latin small letter y U+0079