Simple past tense and past participle of shack.(verb)
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Use "shacked" in a sentence
"If my wife was in a hospital and I had to prove I was married to her, how would I prove that I’m her husband, what if we’re not married and just long term shacked up?"
"Could she have temporarily shacked up with an innocent human?"
"The Shape Of Things To Come: James, seemingly shacked up in his old DHARMA house, is visited by the entity posing as John Locke."