postradiosurgical

The story

1. Proto-Indo-European*pós
2. Proto-Indo-European*pósti
3. Proto-Italic*posti
4. Old Latinposte
5. Latinpost
6. Englishpost-
7. Latinradius
8. Englishradio-
9. Proto-Indo-European*ǵʰes-
10. Proto-Indo-European*ǵʰésōr
11. Proto-Hellenic*kʰéhər
12. Ancient Greekχείρ (kheír)
13. Proto-Indo-European*werǵ-
14. Proto-Indo-European*worǵós
15. Proto-Hellenic*worgós
16. Ancient Greekχειρουργός (kheirourgós)
17. Ancient Greekχειρουργῐκός (kheirourgĭkós)
18. Late Latinchīrurgicus
19. Proto-Indo-European*h₂el-
20. Proto-Indo-European*h₂élisder.?
21. Medieval Latincirurgicālis
22. Middle Frenchcirurgica
23. Middle Englishcirurgical
24. Englishsurgical
25. Englishradiosurgical
26. English todaypostradiosurgical

From post- + radiosurgical.