minoxidil

The story

1. Egyptianjmn
2. Ancient GreekᾸ̓́μμων (Ắmmōn)
3. LatinAmmōn
4. Latinammoniacus
5. Englishammonia
6. Englishamine
7. Englishamino-
8. English(a)mino
9. Proto-Indo-European*h₂eḱ-der.?
10. Ancient Greekὀξύς (oxús)
11. Proto-Indo-European*ǵenh₁-
12. Proto-Indo-European*ǵénh₁os
13. Proto-Hellenic*génos
14. Ancient Greekγένος (génos)
15. Frenchoxygène
16. Proto-Indo-European*h₂eḱ-
17. Proto-Indo-European*h₂eḱéh₁yeti
18. Proto-Italic*akēō
19. Latinaceō
20. Proto-Indo-European*dʰeh₁-
21. Latinacidu
22. Frenchacide
23. Frenchoxide
24. Englishoxid(e)
25. English todayminoxidil

From (a)mino + oxid(e) + -dil (“vasodilator”).