sea lawyer vs Jack

sea lawyer and Jack both are nouns.

Word	Noun	Adjective	Verb	Adverb
sea lawyer	Yes	No	No	No
Jack	Yes	No	No	No

As nouns, Jack is a hypernym of sea lawyer; that is, Jack is a word with a broader meaning than sea lawyer:

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

sea lawyer (noun)	Jack (noun)
an argumentative and contentious seaman	a man who serves as a sailor