Wiktionary
sleep rough
vb. (context idiomatic English) To sleep outdoors, without a place to go home to.
Usage examples of "sleep rough".
Lighter than usual today, in fact, since so many people had gotten out of town, even if only to sleep rough in the countryside for a few days.
She'd go back to Barmouth, sleep rough in one of the shelters on the sea front.
Rather than sleep rough wherever I went I was usually able to rent a room for as long as I intended to stay on each island.
If there are none, I can sleep rough over the night, and in these clothes I can slip in when the morning traffic begins.
Let's go out to the house site today, if we have to we can sleep rough for a while.