shack up vs inhabit

shack up and inhabit both are verbs.

Word	Noun	Adjective	Verb	Adverb
shack up	No	No	Yes	No
inhabit	No	No	Yes	No

As verbs, inhabit is a hypernym of shack up; that is, inhabit is a word with a broader meaning than shack up:

shack up: share living quarters; usually said of people who are not married and live together as a couple
inhabit: be an inhabitant of or reside in

Other hypernyms of shack up include dwell, live, populate.

shack up (verb)	inhabit (verb)
share living quarters; usually said of people who are not married and live together as a couple	be an inhabitant of or reside in
	be present in
	exist or be situated within