IPA: /ˈreɪl.kɑːr/
KK: /ˈreɪlˌkɑr/
A vehicle that runs on tracks and is used for transporting goods or passengers by train.
The railcar was filled with passengers traveling to the city.
Railcar → It is formed from "rail" (from Old French *raille*, meaning a bar or rod) and "car" (from Latin *carrus*, meaning a wheeled vehicle). The word "railcar" refers to a wheeled vehicle that runs on rails.
Think of a 'bar' or 'rod' ('rail') that supports a 'wheeled vehicle' ('car') — that's why a railcar is a vehicle that runs on rails.
No commonly confused words.