Etymology tree Proto-Indo-European *bʰeh₂-der. Proto-Hellenic *pʰáňňō Ancient Greek φαίνω (phaínō) Ancient Greek φαινόμενον (phainómenon)bor. Late Latin phaenomenonder. English phenomenon From Late Latin phaenomenon (“appearance”), from Ancient Greek φαινόμενον (phainómenon, “thing appearing to view”), neuter present middle participle of φαίνω (phaínō, “I show”).