electrosurgically

The story

1. Frenchélectro-
2. Ancient Greekἤλεκτρον (ḗlektron)
3. Latinēlectrum
4. Latinelectro-
5. Englishelectro-
6. Proto-Indo-European*ǵʰes-
7. Proto-Indo-European*ǵʰésōr
8. Proto-Hellenic*kʰéhər
9. Ancient Greekχείρ (kheír)
10. Proto-Indo-European*werǵ-
11. Proto-Indo-European*worǵós
12. Proto-Hellenic*worgós
13. Ancient Greekχειρουργός (kheirourgós)
14. Ancient Greekχειρουργῐκός (kheirourgĭkós)
15. Late Latinchīrurgicus
16. Proto-Indo-European*h₂el-
17. Proto-Indo-European*h₂élisder.?
18. Medieval Latincirurgicālis
19. Middle Frenchcirurgica
20. Middle Englishcirurgical
21. Englishsurgical
22. Englishelectrosurgical
23. Proto-Indo-European*leyg-
24. Proto-Germanic*līką
25. English todayelectrosurgically

From electrosurgical + -ly.