Then I'd suggest you properly attribute them for the data, especially if you're going to charge people for access (in my opinion, IANAL). See their site on the matter:

http://wordnet.princeton.edu/wordnet/citing-wordnet/

You're right, of course. I turned the "about" page on. Was holding off until I could spruce it up a bit, but I guess it's ok for now. Wasn't expecting hackernews to really jump on this.

On their site it says: "Due to funding and staffing issues, we are no longer able to accept comment and suggestions."

What if you give a % of your revenue to them to help them, in return you could be the recommended API on their site?

aren't we supposed to cite the use of WordNet?