IPA: /ˈtreɪnˌmæn/
KK: /trɛnˌmæn/
A person who works on a train, usually as part of the crew that operates it, and may have specific duties like managing the brakes or assisting the conductor.
The trainman ensured that all passengers were safely on board before the train departed.
Trainman → It is formed from "train" (from Old French *traïner*, meaning to pull or drag) and "man" (from Old English *mann*, meaning human being). The word "trainman" refers to a person who operates or works on a train.
Think of someone who 'pulls' or 'drags' a train ('train') and is a 'human being' ('man') — that's why a trainman is someone who works with trains.