The story
- Proto-Italic*wre-
- Latinre-
- Old Frenchre-
- Middle Englishre-
- Englishre-
- Proto-Indo-European*wed-
- Proto-Indo-European*wódr̥
- Proto-Hellenic*údōr
- Ancient Greekῡ̆̔́δωρ (hū̆́dōr)
- Ancient Greekὑδρο- (hudro-)
- Frenchhydro-
- Proto-Indo-European*ǵenh₁-
- Proto-Indo-European*ǵénh₁os
- Proto-Hellenic*génos
- Ancient Greekγένος (génos)
- Frenchhydrogène
- Englishhydrogen
- Englishhydrogenation
- English todayrehydrogenation
From re- + hydrogenation.
Etymology from Wiktionary, CC BY-SA 4.0.