That gave me an idea for an app which would permute all phrases of any length randomly and have forward and back pointers to the next and previous word in the series. At the end of an _n_ word phrase, the next link would give you an _n_+1 phrase.

If a crawler came along (like archive.org) it might index all permutations, giving you some evidence of when your site “coined” a phrase.

The app may want to consult a recent USPTO dump you avoid known trademarks and copyrights. Sounds like a fun exercise.