IPA: /ˈflæt.kɑːr/
KK: /ˈflætˌkɑr/
A type of railroad car that has a flat surface and is used to transport goods, typically without any sides or roof.
The flatcar was loaded with heavy machinery for transport across the country.
Flatcar → The word is formed from "flat" (from Old English *flet*, meaning level or even) and "car" (from Old French *carre*, meaning a vehicle or cart). A flatcar is a type of vehicle that is level and used for transporting goods.
Think of something that is 'level' ('flat') and a 'vehicle' ('car') — a flatcar is a vehicle that is flat and used for carrying things.