tetrahydroxyborate

The story

1. Proto-Indo-European*kʷetwóres
2. Proto-Hellenic*kʷétwores
3. Ancient Greekτέσσᾰρες (téssăres)
4. Ancient Greekτετρᾰ- (tetră-)
5. Englishtetra-
6. Ancient Greekὑδρο- (hudro-)
7. Frenchhydro-
8. Frenchhydrogène
9. Englishhydrogen
10. Proto-Indo-European*h₂eḱ-der.?
11. Ancient Greekὀξύς (oxús)
12. Proto-Indo-European*ǵenh₁-
13. Proto-Indo-European*ǵénh₁os
14. Proto-Hellenic*génos
15. Ancient Greekγένος (génos)
16. Frenchoxygène
17. Englishoxygen
18. Ancient Greekῡ̔́λη (hū́lē)
19. Englishhydroxyl
20. Englishhydroxy-
21. Englishborate
22. English todaytetrahydroxyborate

From tetra- + hydroxy- + borate.