chairman

The story

1. Proto-Indo-European*ḱe?
2. Proto-Indo-European*ḱóm
3. Proto-Indo-European*ḱm̥-th₂der.?
4. Proto-Hellenic*kətá
5. Ancient Greekκατά (katá)
6. Proto-Indo-European*sed-
7. Proto-Indo-European*sedreh₂
8. Proto-Hellenic*hédrā
9. Ancient Greekἕδρα (hédra)
10. Ancient Greekκᾰθέδρᾱ (kăthédrā)
11. Latincathedra
12. Old Frenchchaiere
13. Middle Englishchayere
14. Englishchair
15. Proto-Indo-European*mon-
16. Proto-Germanic*mann-
17. Proto-West Germanic*mann
18. Old Englishmann
19. Middle Englishman
20. English todaychairman

From chair + -man.