sailor vs Navy SEAL

sailor and Navy SEAL both are nouns.

Word	Noun	Adjective	Verb	Adverb
sailor	Yes	No	No	No
Navy SEAL	Yes	No	No	No

As nouns, Navy SEAL is a hyponym of sailor; that is, Navy SEAL is a word with a more specific, narrower meaning than sailor:

sailor: a serviceman in the navy
Navy SEAL: a member of a Naval Special Warfare unit who is trained for unconventional warfare

Other hyponyms of sailor include coastguardsman, SEAL, striker, submariner.

sailor (noun)	Navy SEAL (noun)
a stiff hat made of straw with a flat crown	a member of a Naval Special Warfare unit who is trained for unconventional warfare
any member of a ship's crew
a serviceman in the navy