But you will come across a lot of words used in definitions that could easily be replaced with more common words. In some cases the change to the definition would be tiny, in others it might be more significant.
It seems like a good start. Once you do that, you could start finding vertices with large amounts of incoming edges, attempt to redefine the word as a phrase composed of only words still in the graph, remove that vertex, and repeat.
That will get you much closer but it does ignore the ability to apply creativity to definitions to further reduce them. In the end, a machine-driven technique can give an approximate answer to this problem but it will never be the "perfect" answer.
