In Italian usurajo (an older spelling of usuraio), usurer is whoever lends money at abusive interest. It is the label the town sticks on Vitangelo for being the son and heir of a banker, the same one Marco di Dio gave his father. The crowd shouts it at the eviction, before trading it for "mad."
Where It Appears
Quotes
Ah, there it is: a usurer to the others; a fool here, to Dida, my wife. I was Gengè; a fool here, in her mind and before my wife's eyes.
Well, but this, precisely this, was the “vital point” wounded in me, which blinded me and at that moment took from me the understanding of everything: that I was not a usurer, that usurer I had never been for myself, and now I no longer wanted to be one even for others, and would no longer be one, even at the cost of the ruin of every condition of my life.
Book V: The vital point, Vitangelo Moscarda, on the reason he cannot tell Quantorzo
I was becoming “one.” I. I, who now wanted myself this way. I, who now felt myself this way. At last. No longer a usurer (enough of that bank!): and no longer Gengè (enough of that puppet!).
That vital point that had felt itself wounded in me, when my wife laughed on hearing me say that I no longer wanted to be counted as a usurer in Richieri, was God, beyond any doubt: God, who had felt himself wounded in me, God, who in me could no longer bear that others, in Richieri, should count me as a usurer.