The New Dictionary of Cultural Literacy, Third Edition. 2002.
obscenity
Behavior, appearance, or expression (such as films and books) that violate accepted standards of sexual morality. American courts have long tried to define obscenity but without much success. Some believe, for example, that any depiction of nudity is obscene; others would argue that nudity in itself is not obscene. (Seefour-letter wordsandpornography.)