fireman vs fire marshal

fireman and fire marshal both are nouns.

Word	Noun	Adjective	Verb	Adverb
fireman	Yes	No	No	No
fire marshal	Yes	No	No	No

As nouns, fire marshal is a hyponym of fireman; that is, fire marshal is a word with a more specific, narrower meaning than fireman:

Other hyponyms of fireman include fire chief, fire warden, forest fire fighter, ranger.

fireman (noun)	fire marshal (noun)
play in which children pretend to put out a fire	the head of a fire department
a member of a fire department who tries to extinguish fires
a laborer who tends fires (as on a coal-fired train or steamship)
a pitcher who does not start the game