Here is a definition of a word found within Masonic ritual that is not common outside of Masonic Lodge rooms.
Parallelepipedon. The Entered Apprentice hears this word as a description of ‘the form of the lodge’. Every Entered Apprentice I’ve spoken with after his Initiation admits that he has never before heard the word parallelepipedon. And he has no idea what it means. I try to help with the explanation that it is a shape defined in the first English translation of the works of the geometrician Euclid: that of having six sides of which the opposite sides are parallel.

And I can add that in this year of 2020, the word parallelepipedon is now 550 years old! A detailed explanation of my research is accepted for publication in Ars Quatuor Cornonati 133, November 2020. Subscribe at www.quatuorcoronati.com