Word of the Day: Periplum

This past week at Conflux in NYC, I met Brian House, creator of the Yellow Arrow mapping project, who introduced me to the word "periplum" (click video link for definition). I'm surprised the term is not much mentioned in relation to Williams' Paterson, although, I also wonder how deep it's buried in the Cantos, and how long it took to harden into a concept that could survive its original context. After all, Pound didn't append each canto with a "word box." Any clues about the origins and trajectory of this term would be appreciated. One of Brian's projects is Periplurban: An Urban Experiential Dictionary, which was created with his students as part of a workshop at Columbia's School of Architecture, Planning, and Preservation.