How many times have you heard or used the terms "pirouette" or "pas de deux" without really knowing what they meant? A number of words related to ballet have made their way into common usage, although many people may not know what they really mean or what they would look like if performed by a trained dancer. The American Ballet Theatre has created this Online Ballet Dictionary of 170 terms with assistance from its own dancers who were asked to "show us how it is supposed to be done." The resulting site combines Quicktime movies of dancers demonstrating steps with terms drawn from the Technical Manual and Dictionary of Classical Ballet. While not every term is accompanied by a movie, each term includes a definition and pronunciation guide, as well as occasional cross references to other terms in the dictionary.