ephemeron ephemeromorphic • Ephemeroptera · · · Info · Definitions · Synonyms · Characters · · ephemeron · · Text Latin · · Script 9 · · Length Definitions · · · (noun) anything short-lived, as an insect that lives only for a day in its winged form. Synonyms: ephemeral. · · Noun Definition 1 Synonyms · · · ephemeral · · Synonym 1 Characters · · e latin small letter e U+0065 h latin small letter h U+0068 m latin small letter m U+006D 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