The unified password checker/cracker/generator
1. What is a dictionary file? A dictionary file contains multiple passwords, with each of those passwords occupying its own line. Dictionary files are commonly used to check or crack passwords, and if you are using a Unix OS, you should already have at least one dictionary file. In Linux, the files are usually located in /usr/dict/ with a symbolic link /usr/dict/words->someDictFile, in the event of multiple files.
You can download this tarball which contains several dictionary files of various sizes.
Remember, the larger the dictionary file, the slower it will take to crack a password file, but your chances increase to find matches.