arseniferous

The story

1. Proto-Indo-European*ǵʰelh₃-
2. Proto-Indo-European*ǵʰl̥h₃enyom
3. Proto-Indo-Iranian*ȷ́ʰr̥Hanyam
4. Proto-Iranian*jr̥Hanyam
5. Old Median*zaranyam
6. Old Median*kā
7. Old Median*zaraniyakā
8. Middle Persian*zarnīk
9. Classical Syriacܙܪܢܝܟܐ (zarnīḵā)
10. Arabicالزَرْنِيخ (az-zarnīḵ)
11. Medieval Greekἀρσενικόν (arsenikón)
12. Latinarsenicum
13. Middle Frencharsenic
14. Middle Englisharsenik
15. Englisharsenic
16. Proto-Indo-European*bʰer-
17. Proto-Indo-European*bʰéreti
18. Proto-Italic*ferō
19. Latinferō
20. Proto-Indo-European*h₃ed-
21. Proto-Indo-European*h₃édosder.?
22. English todayarseniferous

From arsenic + -iferous.