IPA: //ˈreɪlˌbʌs//
KK: /ˈreɪlˌbʌs/
A lightweight vehicle designed for carrying passengers on railway tracks, resembling a bus in shape and function.
The railbus made the journey from the small town to the city much faster than the traditional train.
Railbus → The word is formed from "rail" (from Old French *raille*, meaning a bar or rod) and "bus" (from Latin *omnibus*, meaning for all). A railbus refers to a bus designed to run on railway tracks, combining the concepts of rail transport and bus service.
Think of a 'bar' or 'rod' ('rail') that is designed for 'everyone' ('bus') to use — that's why a railbus is a vehicle that operates on train tracks for public transport.