'Shack up' definitions:
Definition of 'shack up'
From: WordNet
verb
Share living quarters; usually said of people who are not married and live together as a couple [syn: cohabit, live together, shack up]
Definition of 'Shack up'
From: GCIDE
- Shack up \Shack" up`\, v. i.
- 1. to live together in a sexual relationship, without being legally married. [Slang, U. S.] [PJC]
- 2. to live in a cabin, shack, or other crude dwelling. [Slang, U. S.] [PJC]