antibaryon

The story

1. Proto-Indo-European*h₂ent-
2. Proto-Indo-European*h₂énts
3. Proto-Indo-European*h₂énti
4. Ancient Greekᾰ̓ντῐ́ (ăntĭ́)
5. Ancient Greekἀντι- (anti-)
6. Englishanti-
7. Proto-Indo-European*gʷreh₂-
8. Proto-Indo-European*gʷréh₂us
9. Proto-Hellenic*gʷarus
10. Ancient Greekβαρύς (barús)
11. Ancient Greekἤλεκτρον (ḗlektron)
12. Latinēlectrum
13. New Latinēlectricus
14. Englishelectric
15. Proto-Indo-European*h₁ey-
16. Proto-Indo-European*h₁éyti
17. Proto-Hellenic*éimi
18. Ancient Greekἰόν (ión)
19. Englishion
20. Englishelectronbf.
21. Englishbaryon
22. English todayantibaryon

From anti- + baryon.