Likely that came from author Gene Wolfe. He has a habit of using unusual words. Sometimes he'll make one up entirely or use an archaic/abstruse word from ancient times. 

Defenestration was a method of execution taught to one of Wolfe's characters - an official torturer by trade in a future world. 

Another word from that same text was "autochthonous" (sic) - which was once the winning word in the final round of a major spelling bee. It means "primitive/indigenous" as in a non-technological culture. I remember reading about that and laughing out loud because I am not a great speller, but I knew how to spell that word (sort of like "chthonic" - which means, "related to the Underworld/Hell") . I also taught myself to spell "antidisestablishmentarianism" as a boy. 

But that's about the most unusual thing about me. Other than being almost-indescribably handsome.