automatically

The story

1. Proto-Indo-European*h₂ew
2. Proto-Indo-European*tó-
3. Proto-Hellenic*autós
4. Proto-Indo-European*h₂ew
5. Ancient Greekαὖ (aû)
6. Ancient Greekτόν (tón)
7. Ancient Greekαὐτός (autós)
8. Ancient Greekαὐτο- (auto-)
9. Proto-Indo-European*men-
10. Proto-Indo-European*mn̥tós
11. Proto-Hellenic*mətós
12. Ancient Greekαὐτόμᾰτος (autómătos)
13. Ancient Greekαὐτόμᾰτον (autómăton)
14. Classical Latinautomatum
15. New Latinautomaticus
16. Englishautomatic
17. Proto-Indo-European*h₂el-
18. Proto-Indo-European*h₂élisder.?
19. Proto-Indo-European*leyg-
20. Proto-Germanic*līką
21. English todayautomatically

From automatic + -ally.