heterocyclic

The story

1. Proto-Indo-European*sem-
2. Proto-Indo-European*sḿ̥teros
3. Proto-Hellenic*hə́teros
4. Ancient Greekἕτερος (héteros)
5. Englishhetero-
6. Proto-Indo-European*kʷelh₁-redup.
7. Proto-Indo-European*kʷékʷlos
8. Proto-Hellenic*kʷókʷlos
9. Proto-Hellenic*kúklos
10. Ancient Greekκύκλος (kúklos)
11. Ancient Greekκυκλῐκός (kuklĭkós)
12. Classical Latincyclicu
13. Middle Frenchcyclique
14. Frenchcyclique
15. Classical Latincyclicus
16. Englishcyclic
17. English todayheterocyclic

From hetero- + cyclic.