To sleep somewhere other than one's home, especially in the outdoors. My brother and I loved setting up our tent in the field behind our house so we could sleep out during the summer months.
sleep out
to sleep outside or away from one's home. Can I sleep out tonight? Didn't you sleep out last night?
sleep out
1. Sleep at home, as opposed to one's place of employment, as in We have a full-time nurse for her, but she sleeps out. [Mid-1800s]
2. Sleep away from one's own home, as in She's not here; she's sleeping out.
sleep out
v.
1. To sleep away from one's home: I will be sleeping out tonight, so don't wait up.
2. To sleep at one's own home, not at one's place of employment: The maid sleeps out Mondays, so we'll have the house to ourselves.