Shack up and Tie down

Shack up verb - Share living quarters; usually said of people who are not married and live together as a couple.

Tie down and shack up are semantically related. In some cases you can use "Tie down" instead a verb "Shack up".

Tie down verb - Secure with or as if with ropes.

Shack up and tie down are semantically related. Sometimes you can use "Shack up" instead a verb "Tie down".