WordNet
n. vulgar and offensive nakedness in a public place [syn: indecent exposure]
Wikipedia
Public nudity, or nude in public (NIP), refers to nudity not in an entirely private context, that is, a person appearing nude in a public place or being able to be seen nude from a public place. Nudity on private property but where the general public is commonly free to enter, such as a shopping mall, public transport or swimming pool, is also considered public nudity. Nudity in the privacy of a person's home or grounds is not considered public nudity, nor is nudity at privately owned facilities where nudity commonly takes place, such as gymnasia, locker rooms, saunas, or specific nudist clubs or resorts. Naturism is a movement that promotes social nudity in nature, most but not all of which takes place on private property.