microsurgically

The story

1. Proto-Indo-European*mey-der.?
2. Ancient Greekμῑκρός (mīkrós)
3. Ancient Greekμῑκρο- (mīkro-)
4. Englishmicro-
5. Proto-Indo-European*ǵʰes-
6. Proto-Indo-European*ǵʰésōr
7. Proto-Hellenic*kʰéhər
8. Ancient Greekχείρ (kheír)
9. Proto-Indo-European*werǵ-
10. Proto-Indo-European*worǵós
11. Proto-Hellenic*worgós
12. Ancient Greekχειρουργός (kheirourgós)
13. Ancient Greekχειρουργῐκός (kheirourgĭkós)
14. Late Latinchīrurgicus
15. Proto-Indo-European*h₂el-
16. Proto-Indo-European*h₂élisder.?
17. Medieval Latincirurgicālis
18. Middle Frenchcirurgica
19. Middle Englishcirurgical
20. Englishsurgical
21. Englishmicrosurgical
22. Proto-Indo-European*leyg-
23. Proto-Germanic*līką
24. English todaymicrosurgically

From microsurgical + -ly.