phosphatase

The story

1. Proto-Indo-European*bʰeh₂-
2. Proto-Indo-European*bʰéh₂os
3. Proto-Hellenic*pʰáwos
4. Ancient Greekφᾰ́ος (phắos)
5. Ancient Greekφῶς (phôs)
6. Proto-Indo-European*bʰer-
7. Proto-Indo-European*bʰéreti
8. Proto-Hellenic*pʰérō
9. Ancient Greekφέρω (phérō)
10. Ancient Greekφωσφόρος (phōsphóros)
11. Latinphōsphorus
12. Frenchphosphore
13. Frenchphosphate
14. Englishphosphate
15. Proto-Indo-European*dwóh₁
16. Proto-Indo-European*trísinflu.
17. Proto-Indo-European*dwís
18. Ancient Greekδιά (diá)
19. Ancient Greekδῐᾰ- (dĭă-)
20. Proto-Indo-European*steh₂-
21. Proto-Indo-European*stísteh₂ti
22. Proto-Hellenic*hístāmi
23. Ancient Greekῐ̔́στημῐ (hĭ́stēmĭ)
24. Ancient Greekδῐῐ̈́στημῐ (dĭĭ̈́stēmĭ)
25. Ancient Greekδῐᾰ́στᾰσῐς (dĭắstăsĭs)
26. Englishdiastase
27. English todayphosphatase

From phosphate + -ase.