shack up vs cohabit

shack up and cohabit both are verbs.

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

As verbs, shack up and cohabit are synonyms defined as:

shack up and cohabit: share living quarters; usually said of people who are not married and live together as a couple

Other synonyms of shack up include live together.

shack up (verb)	cohabit (verb)
share living quarters; usually said of people who are not married and live together as a couple	share living quarters; usually said of people who are not married and live together as a couple
	exist together