roustabout vs sea dog

roustabout and sea dog both are nouns.

Word	Noun	Adjective	Verb	Adverb
roustabout	Yes	No	No	No
sea dog	Yes	No	No	No

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

Other hypernyms of roustabout include gob, Jack-tar, Jack, mariner, old salt, seafarer, seaman, tar.

roustabout (noun)	sea dog (noun)
a member of a ship's crew who performs manual labor	a man who serves as a sailor