You can't copyright a database of publicly available information (e.g. a dictionary, a phone book etc.): http://en.wikipedia.org/wiki/Feist_Publications_v._Rural_Tel...

Some dictionaries have been inserting a fake word into their lists so that they can copyright that specific word and go after the infringer for using that word in their dictionaries. They can also copyright the definition of words. But you can't copyright Scrabble's list of acceptable words.