railroad man vs railroader

railroad man and railroader both are nouns.

Word	Noun	Adjective	Verb	Adverb
railroad man	Yes	No	No	No
railroader	Yes	No	No	No

As nouns, railroad man and railroader are synonyms defined as:

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

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