Literary or artistic items having an erotic theme. It refers especially to books treating sexual love in a sensuous or voluptuous manner. (Webster, 3d ed)
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
A verbal or nonverbal means of communicating ideas or feelings.