We have created our own dictionary using various sources to ensure that we have a good selection of words available for use within the game. We have given priority to the most common and popular words while also allowing some relatively obscure words for people who like a challenge!
On occasion you may find that the game doesn't accept a word you are trying to enter. If the word is potentially vulgar, smutty, offensive, or otherwise objectionable, it could be that the Kid Safe option is blocking the word. If you are an adult, you can turn this setting OFF in the Options screen.
If you have the Kid Safe option set to OFF and the game is still not accepting a word you consider valid, please submit the word using the in-game feedback form or create a new support ticket.