The story
- Proto-Indo-European*h₂ew
- Proto-Indo-European*tó-
- Proto-Hellenic*autós
- Proto-Indo-European*h₂ew
- Ancient Greekαὖ (aû)
- Ancient Greekτόν (tón)
- Ancient Greekαὐτός (autós)
- Ancient Greekαὐτο- (auto-)
- Frenchauto-
- Proto-Indo-European*m(y)ewh₁-
- Proto-Indo-European*m(y)owh₁éyeti
- Proto-Italic*moweō
- Latinmoveō
- Latinmōbili
- Frenchmobile
- Frenchautomobile
- Englishautomobileclip.
- Englishauto-
- Proto-Indo-European*h₃ep-
- Proto-Italic*opnis
- Latinomnis
- Latinomnibu
- Frenchomnibus
- Englishomnibusclip.
- Englishbus
- English todayautobus
From auto- (prefix meaning ‘self’, in the sense of being self-propelled) + bus. Sense 2 (“large group of cyclists who have fallen behind the peloton”) is borrowed from French autobus.
Etymology from Wiktionary, CC BY-SA 4.0.