able-bodied seaman vs Jack-tar

able-bodied seaman and Jack-tar both are nouns.

Word	Noun	Adjective	Verb	Adverb
able-bodied seaman	Yes	No	No	No
Jack-tar	Yes	No	No	No

As nouns, Jack-tar is a hypernym of able-bodied seaman; that is, Jack-tar is a word with a broader meaning than able-bodied seaman:

able-bodied seaman: a seaman in the merchant marine; trained in special skills
Jack-tar: a man who serves as a sailor

Other hypernyms of able-bodied seaman include gob, Jack, mariner, old salt, sea dog, seafarer, seaman, tar.

able-bodied seaman (noun)	Jack-tar (noun)
a seaman in the merchant marine; trained in special skills	a man who serves as a sailor