trainmaster vs railway man

trainmaster and railway man both are nouns.

Word	Noun	Adjective	Verb	Adverb
trainmaster	Yes	No	No	No
railway man	Yes	No	No	No

As nouns, railway man is a hypernym of trainmaster; that is, railway man is a word with a broader meaning than trainmaster:

Other hypernyms of trainmaster include dispatcher, railroad man, railroader, railwayman, trainman.

trainmaster (noun)	railway man (noun)
a railroad employer who is in charge of a railway yard	an employee of a railroad