The story
- Proto-Indo-European*h₁éǵʰ
- Proto-Indo-European*h₁éǵʰs
- Proto-Indo-European*h₁eǵʰsteros
- Proto-Italic*eksteros
- Latinexter
- Latinextrā
- Englishextra-
- Proto-Indo-European*bʰeh₂-
- Proto-Indo-European*bʰh₂nyéti
- Proto-Hellenic*pʰáňňō
- Ancient Greekφαίνω (phaínō)
- Ancient Greekφαινόμενον (phainómenon)
- Late Latinphaenomenon
- Englishphenomenon
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Ancient Greekφαινόμενον (phainómenon)
- Frenchphénomène
- Frenchphénoména
- Englishphenomenal
- English todayextraphenomenal
From extra- + phenomenal.
Etymology from Wiktionary, CC BY-SA 4.0.