trainman vs railway man

trainman and railway man both are nouns.

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

As nouns, trainman and railway man are synonyms defined as:

Other synonyms of trainman include railroad man, railroader, railwayman.

trainman (noun)	railway man (noun)
an employee of a railroad	an employee of a railroad