The story
- Ancient Greekῐ̓́σος (ĭ́sos)
- Englishiso-
- Proto-Indo-European*h₁éǵʰ
- Proto-Indo-European*h₁éǵʰs
- Proto-Italic*eks
- Latinex
- Latinex-
- Proto-Indo-European*dʰeh₁-
- Proto-Indo-European*dʰeh₁k-
- Proto-Indo-European*dʰh₁kyéti
- Proto-Italic*θakjō
- Proto-Italic*fakjō
- Latinfaciō
- Latinefficiō
- Latineffectīvu
- Frencheffectif
- Englisheffective
- Englisheffectively
- English todayisoeffectively
From iso- + effectively.
Etymology from Wiktionary, CC BY-SA 4.0.