The story
- Proto-Indo-European*de
- Proto-Indo-European*déh₁
- Proto-Italic*dē
- Latindē
- Latinde-
- Proto-Indo-European*dʰeh₁-
- Proto-Indo-European*dʰeh₁k-
- Proto-Indo-European*dʰh₁kyéti
- Proto-Italic*θakjō
- Proto-Italic*fakjō
- Latinfacio
- Latindēficiō
- Latindēfectus
- Englishdefect
- Proto-Indo-European*leǵ-
- Proto-Indo-European*lóǵos
- Proto-Hellenic*lógos
- Ancient Greekλόγος (lógos)
- Englishdefectology
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- English todaydefectological
From defectology + -ical.
Etymology from Wiktionary, CC BY-SA 4.0.