hundo

The story

1. Proto-Indo-European*déḱm̥
2. Proto-Indo-European*ḱm̥tóm
3. Proto-Germanic*hundą
4. Proto-Indo-European*h₂er-
5. Proto-Indo-European*h₂reh₁-
6. Proto-Indo-European*dʰeh₁-
7. Proto-Indo-European*Hreh₁dʰ-
8. Proto-Indo-European*h₂r̥h₁dʰ-éh₂
9. Proto-Germanic*radō
10. Proto-Germanic*radą
11. Proto-Germanic*hundaradą
12. Proto-West Germanic*hundarad
13. Old Englishhundred
14. Middle Englishhundred
15. Englishhundred
16. Latinō
17. Old Frenchoh
18. Middle Englisho
19. EnglishO
20. Middle Englisho
21. Englishoh
22. English todayhundo

From hundred + -o.