1. To move in to shared acommodation with someone, generally of the opposite sex for purposes of sexual intercourse.
I'm shacked up with a few sheilas.
by sasquatchian May 30, 2005
To hunker down; to base yourself out of a location; a place of respite.
"We're going to shack-up at Joe's for the weekend since we don't want to pay for a hotel room." OR "I'm shacked-up at home, but I'll meet you there."
by fozbend August 28, 2006