navy man vs military man

navy man and military man both are nouns.

Word	Noun	Adjective	Verb	Adverb
navy man	Yes	No	No	No
military man	Yes	No	No	No

As nouns, military man is a hypernym of navy man; that is, military man is a word with a broader meaning than navy man:

navy man: a serviceman in the navy
military man: someone who serves in the armed forces; a member of a military force

Other hypernyms of navy man include man, military personnel, serviceman.

navy man (noun)	military man (noun)
a serviceman in the navy	someone who serves in the armed forces; a member of a military force