bare-butt

• barebutt

bare (“naked”) +‎ butt (“bottom”).

bare-butt (not comparable)

1. (Canada, US, slang) With the butt exposed, as for a spanking or a mooning.
2. (Canada, US, slang, by extension) Stark naked.
   • 2001, Thom Akeman, Monterey Peninsula: A Cypress Shore, Graphic Arts Center Publishing (2001), →ISBN, page 7:

     It has taken millions of years of evolution — pelagic, geologic, biological, and cultural — to create the Monterey Peninsula of today, a charming series of communities that appeal to bare-butt, stoned-out hippies as much as to some of the wealthiest and most talented people in the world.

   • 2005, Tim Burford, Chile: The Bradt Travel Guide, Globe Pequot Press (2005), →ISBN, page 369:

     Although Horcón has tolerated bare-butt bathing for some years, the municipalidad of Pichilemu wants to be the first to officially accept nudism, despite the opposition of its parish priest, who declared 'nudism leads to adultery'.

   • 2009, Stuart Holmes Coleman, Fierce Heart: The Story of Makaha and the Soul of Hawaiian Surfing, St. Martin's Press (2009), →ISBN, unnumbered page:

     […] All the while, he's paddling toward the beach, and when he got up there, the shark was cruising around on the inside. So he took his shorts off, threw them to the shark and just walked bare-butt down the beach. […]

• bare-arse
• bareass
• bare-bum