zillionaire

The story

1. Englishzillion
2. Proto-Indo-European*sem-
3. Proto-Indo-European*sm̥-
4. Proto-Indo-European*smih₂
5. Proto-Indo-European*ǵʰes-
6. Proto-Indo-European*ǵʰéslom
7. Proto-Indo-European*ǵʰéslih₂
8. Proto-Indo-European*smih₂ǵʰéslih₂
9. Proto-Italic*smīɣeslī
10. Latinmīlle
11. Italianmille
12. Italianmilione
13. Old Frenchmillion
14. Middle Frenchmillion
15. Frenchmillion
16. Frenchmillionnaire
17. Englishmillionaire
18. English todayzillionaire

From zillion + -aire.