IPA: /ˈreɪlˌroʊdər/
KK: /ˈreɪlˌroʊdər/
A person who works for a company that operates trains and manages rail transport.
My uncle is a railroader who has been working on the trains for over twenty years.
Railroader → It is formed from "rail" (from Old French *raille*, meaning a bar or beam) and "-roader" (meaning a person who works with or on roads). The word "railroader" refers to a person who works on or with railways, which are essentially roads made of rails.
Think of someone who works on the 'rails' — that's why a 'railroader' is a person involved with railways.