[oh_sigh]

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.

[clhodapp]

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.