Refers to the conditions of the Guantanamo Bay Detention Camp located in Cuba. One might describe their night, current situation, or future as Guantany if the state of things is so bad it rivals in the conditions of this infamous prison camp.
Person 1: "Dude I slept on a cement floor last night and woke up with a fucking mouse trap in my hair"
Person 2: "Seriously dude? Why didn't you find a couch or something?"
Person 1: "We got locked in the goddamn basement. That whole night was so fucking Guantany I don't even want to talk about it."