peptidase

The story

1. Proto-Indo-European*pekʷ-
2. Proto-Indo-European*pékʷ-ye-
3. Proto-Hellenic*pét͏̌t͏̌ō
4. Ancient Greekπέσσω (péssō)bf.
5. Ancient Greekπέπτω (péptō)
6. Ancient Greekπεπτόν (peptón)
7. GermanPepton
8. Englishpeptone
9. Proto-Indo-European*dʰeh₁-
10. GermanPepton
11. GermanPeptid
12. Englishpeptide
13. Proto-Indo-European*dwóh₁
14. Proto-Indo-European*trísinflu.
15. Proto-Indo-European*dwís
16. Ancient Greekδιά (diá)
17. Ancient Greekδῐᾰ- (dĭă-)
18. Proto-Indo-European*steh₂-
19. Proto-Indo-European*stísteh₂ti
20. Proto-Hellenic*hístāmi
21. Ancient Greekῐ̔́στημῐ (hĭ́stēmĭ)
22. Ancient Greekδῐῐ̈́στημῐ (dĭĭ̈́stēmĭ)
23. Ancient Greekδῐᾰ́στᾰσῐς (dĭắstăsĭs)
24. Englishdiastase
25. English todaypeptidase

From peptide + -ase.