'autorail' originates from French, specifically the word 'autorail', where 'auto-' meant 'self' and 'rail' meant 'rail'.

'autorail' was coined in French in the early 20th century as a compound of 'auto' + 'rail' to denote motorized rail vehicles, and the term was later borrowed into English in technical and historical contexts.

Initially it could refer to an automobile adapted to run on rails or early motorized rail vehicles; over time it came to mean any self-propelled passenger railcar or railbus.