train dispatcher vs railwayman

train dispatcher and railwayman both are nouns.

Word	Noun	Adjective	Verb	Adverb
train dispatcher	Yes	No	No	No
railwayman	Yes	No	No	No

As nouns, railwayman is a hypernym of train dispatcher; that is, railwayman is a word with a broader meaning than train dispatcher:

Other hypernyms of train dispatcher include dispatcher, railroad man, railroader, railway man, trainman.

train dispatcher (noun)	railwayman (noun)
a railroad employer who is in charge of a railway yard	an employee of a railroad