yardmaster vs railroader

yardmaster and railroader both are nouns.

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

As nouns, railroader is a hypernym of yardmaster; that is, railroader is a word with a broader meaning than yardmaster:

Other hypernyms of yardmaster include dispatcher, railroad man, railway man, railwayman, trainman.

yardmaster (noun)	railroader (noun)
a railroad employer who is in charge of a railway yard	an employee of a railroad