dishabille \dis-uh-BEEL\ (noun) - 1 : The state of being carelessly or partially dressed. 2 : Casual or lounging attire. 3 : An intentionally careless or casual manner.
"Marta's parents were utterly scandalized when they toured her dorm, seeing all the people sho should have been fully clothed lounging around in dishabille."
Dishabille comes from French déshabiller, "to undress," from dés-, "dis-" + habiller, "to clothe, to dress."