cohabit vs shack up

cohabit and shack up both are verbs.

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

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

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

Other synonyms of cohabit include live together.

cohabit (verb)	shack up (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