The story
- Proto-Indo-European*bʰeh₂-
- Proto-Indo-European*bʰéh₂os
- Proto-Hellenic*pʰáwos
- Ancient Greekφᾰ́ος (phắos)
- Ancient Greekφῶς (phôs)
- Ancient Greekφωτο- (phōto-)
- Englishphoto-
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Italic*n̥-
- Latinin-
- Proto-Indo-European*h₂eǵ-
- Proto-Indo-European*h₂éǵeti
- Proto-Italic*agō
- Latinagō
- Ancient Greekἐνεργητικός (energētikós)
- Latināctīvus
- Latinināctīvu
- Frenchinactif
- Englishinactive
- Englishinactivation
- English todayphotoinactivation
From photo- + inactivation.
Etymology from Wiktionary, CC BY-SA 4.0.