1. (US, also shack) a person with whom one has a sexual relationship; also attrib.
|Battle Cry (1964) 192: The men drank and slept with their shackups.|
|One to Count Cadence (1987) 62: His steady shack, Dottie the bow-legged whore.|
|(con. 1920s) Legs 225: You’ll get pieced off like a shack-up broad.|
2. an act of sexual intercourse; also attrib.
|Far from the Customary Skies 58: I’d sure like one shack-up job before we go across.|
|Doom Pussy 168: He’s just come back from a shack-up with her somewhere.|
|Collura (1978) 100: A one-night shack-up at the Beverley Hills Hotel during a vacation.|
3. a sexual relationship.
|in Sweet Daddy 96: They want it all [...] shack ups, gang bangs, sandwiches, the works.|
|Tales of the City (1984) 59: For God’s sake! This isn’t a shack-up!|
|Further Tales of the City (1984) 28: I paid for a weekend shack-up in Sierra City.|