T.H.: With this title you are particularly referring to Pound’s Canto XLV With Usura. Pound himself gave a short definition at the end of the poem. Usury, according to Pound, is the charge for the use of purchasing power, levied without regard for production, and often without regard for the possibilities of production. Pound mentions as a historical example the «failure of the Medici bank».
P.N.: In addition to that there is a double meaning in Portuguese for that word. Usura means also «worn»; you can say «true usura» in the sense of «truly tired», «truly used». Since the word is that ambiguous it was perfect as a title.