The story
- Englishselen-
- Proto-Indo-European*leǵ-
- Proto-Indo-European*lóǵos
- Proto-Hellenic*lógos
- Ancient Greekλόγος (lógos)
- Englishselenology
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- English todayselenological
From selenology + -ical.
Etymology from Wiktionary, CC BY-SA 4.0.