Word list for use in commercial game

I need a word list to use in a commercial game (even though the game will be free to download)

Something like this

http://www.puzzlers.org/pub/wordlists/ospd.txt

Would be perfect (needs to be formatted .txt file) but obviously allowed to be used in a commercial game. I'm happy to pay if it's not too much.

Thanks for any advice.

UPDATE

After some more research (google), I came across this passage. Thought this might be useful for other people, although it still seems in contradiction to what the replies are saying on stack overflow here

"The nearest thing to a licence text for ENABLE, of which ABLE forms a part, is as follows.

The ENABLE master word list, WORD.LST, is herewith formally released into the Public Domain. Anyone is free to use it or distribute it in any manner they see fit. No fee or registration is required for its use nor are "contributions" solicited (if you feel you absolutely must contribute something for your own peace of mind, the authors of the ENABLE list ask that you make a donation on their behalf to your favorite charity). This word list is our gift to the Scrabble community, as an alternate to "official" word lists. Game designers may feel free to incorporate the WORD.LST into their games. Please mention the source and credit us as originators of the list. Note that if you, as a game designer, use the WORD.LST in your product, you may still copyright and protect your product, but you may not legally copyright or in any way restrict redistribution of the WORD.LST portion of your product. This may under law restrict your rights to restrict your users' rights, but that is only fair.

M Cooper and Alan Beale "

From this site http://www.quinapalus.com/dicts.html

Obviously I have no way of knowing if that's legit or not, so I was wondering what other peoples advice still is.

Answer

According to the site you linked your list from:

The official Scrabble player's dictionary, known as OSPD, is widely available on the internet. There is also a list targetted at Scrabble players known as the Enable list. This has been explicitly placed in the public domain.

In addition, the page the link resides on contains numerous other lists of words that are free to use.

EDIT

You found in your update, what I'd already said in my answer. Additionally, the SE link you've posted has plenty of alternative answers. For example: The English Open Word List, has more words that the OSPD and it's restriction free. Beyond that, the Enable list, as I said in my answer, seems to be a very good choice and is in the public domain.