seaman vs sailor

seaman and sailor both are nouns.

Word	Noun	Adjective	Verb	Adverb
seaman	Yes	No	No	No
sailor	Yes	No	No	No

As nouns, sailor is a hypernym of seaman; that is, sailor is a word with a broader meaning than seaman:

Other hypernyms of seaman include crewman.

seaman (noun)	sailor (noun)
a man who serves as a sailor	a stiff hat made of straw with a flat crown
	any member of a ship's crew
	a serviceman in the navy