is the four-dimensional equivalent of a cube. This question took a little research, however, as ol' Cliff doesn't have all of the answers. The first place to look for the definition of a particular word, of course, is the dictionary. If you don't have a print dictionary handy, get on the Internet to check out some of the numerous online dictionaries. Start at the most obvious, Dictionary.com
, and type in "tesseract." Click the "Search" button, and the definition appears. Another nice resource is Wikipedia
, which is more like an encyclopedia than a dictionary, but it's amazingly helpful.