Naturism, or nudism, is a cultural and political movement practicing, advocating, and defending personal and social nudity, most but not all of which takes place on private property. The term may also refer to a lifestyle based on personal, family, or social nudity. Naturism may take a number of forms. It may be practiced individually, within a family, socially, or in public. Additionally, there is also militant naturism, including campaigning, and extreme naturism is sometimes considered a separate category.
That is the definition according to Wikipedia. My definition is:
To enjoy the freedom of the sun on your body without the interference of clothing and to embrace this way of life with like minded individuals. Be Naked as Nature intended.