A type of occasional bed with a three-part metal frame which folds up for storage; (also more generally) any of various types of portable folding bed; cf. zedbedn.
1973
For sale: 1970 VW Bus with sun roof and Z-bed.
Oshkosh (Wisconsin) Daily Northwestern 20 September 31/2 (advertisement)
2001
‘I'd rather sleep on the floor than share with Joe’, said David, hurling himself onto the damp Z-bed under the window.
A type of occasional bed with a three-part metal frame which folds up for storage; (also more generally) any of various types of portable folding… A proprietary name in the United States.