protosome

The story

1. Proto-Indo-European*per-der.?
2. Proto-Indo-European*pér
3. Proto-Indo-European*pró
4. Ancient Greekπρό (pró)
5. Ancient Greekπρῶτος (prôtos)
6. Ancient Greekπρωτο- (prōto-)
7. Englishproto-
8. Proto-Indo-European*tewh₂-
9. Proto-Indo-European*twoH-mn̥
10. Proto-Hellenic*twṓmə?
11. Proto-Indo-European*styeH-
12. Proto-Indo-European*(s)tyoH-mn̥
13. Proto-Hellenic*styṓmə?
14. Ancient Greekσῶμα (sôma)
15. English todayprotosome

From proto- + -some.