nanocompartment

The story

1. Ancient Greekνᾶνος (nânos)
2. Latinnānus
3. Englishnano-
4. Proto-Indo-European*ḱe?
5. Proto-Indo-European*ḱóm
6. Proto-Italic*kom
7. Proto-Italic*kom-
8. Latincom-
9. Proto-Indo-European*perh₃-
10. Proto-Indo-European*pérh₃tis?
11. Proto-Italic*partis
12. Latinpars
13. Latinpartiō
14. Latinpartior
15. Latincompartīrī
16. Italiancompartire
17. Italiancompartimento
18. Middle Frenchcompartiment
19. Englishcompartment
20. English todaynanocompartment

From nano- + compartment.