endotracheal

The story

1. Proto-Indo-European*h₁n̥dóm
2. Proto-Hellenic*éndon
3. Ancient Greekἔνδον (éndon)
4. Englishendo-
5. Proto-Indo-European*dʰreh₂gʰ-
6. Proto-Indo-European*dʰréh₂gʰus
7. Proto-Hellenic*tʰrākʰús
8. Ancient Greekτρᾱχεῖᾰ (trākheîă)
9. Late Latintrāchīa
10. Medieval Latintrāchēa
11. Englishtrachea
12. Proto-Indo-European*h₂el-
13. Proto-Indo-European*h₂élisder.?
14. Englishtracheal
15. English todayendotracheal

From endo- + tracheal.