whaler vs Jack

whaler and Jack both are nouns.

Word	Noun	Adjective	Verb	Adverb
whaler	Yes	No	No	No
Jack	Yes	No	No	No

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

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

whaler (noun)	Jack (noun)
a ship engaged in whale fishing	a man who serves as a sailor
a seaman who works on a ship that hunts whales