Well, did anyone else look it up? I did--on Onelook.com. And there was only one reference cited: The All Powerful Tsuwm's! (I had to capitalize tsuwm here because he deserved capitalization given the fact that out of over 700 dictionaries, his was the only one--and so I quote:

"tetrapyloctomy

"The art of splitting a hair four ways" according to Umberto Eco in Foucault's Pendulum "

Bravo, bravo, bravo!