hay fever hay fern • hayfield · · · Info · Definitions · Synonyms · Characters · · hay fever · · Text Common · · Latin · · Scripts 9 · · Length 3 · · Syllables Definitions · · · (noun) a seasonal rhinitis resulting from an allergic reaction to pollen. Synonyms: hay fever, pollinosis. · · Noun Definition 1 Synonyms · · · pollinosis · · Synonym 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 f latin small letter f U+0066 h latin small letter h U+0068 r latin small letter r U+0072 v latin small letter v U+0076 y latin small letter y U+0079