"Aardvark to Zygote" isn't a "dictionary." It's a compilation of "cross weirds" (words which appear more often in crosswords than in the media or conversation). It is doesn't include the simple words that often appear in crosswords but which the reader/solver no doubt already knows. Nor does it include the difficult words that only a few people would know (or want to know). It includes those "in-between words" which are not commonly used but which, because they use the most common letters of the alphabet, often appear in crosswords. There are two ways to use this collection: If you have the patience, you can use it as a reference to look a particular word. Or you can use it as a study guide, both to improve your crossword-solving skills as well as your general vocabulary. Whichever way you use it, have fun! (Will Shortz [Crossword Editor, The New York Times and Puzzlemaster, NPR] wrote: "AARDVARK TO ZYGOTE is amusing and nice. It's a good thing for crossworders to study.")