railwayman vs railroader

railwayman and railroader both are nouns.

Word	Noun	Adjective	Verb	Adverb
railwayman	Yes	No	No	No
railroader	Yes	No	No	No

As nouns, railwayman and railroader are synonyms defined as:

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

railwayman (noun)	railroader (noun)
an employee of a railroad	an employee of a railroad