Usury
Etymology
From Medieval Latin usuria, from Latin usura, "interest paid for the use of money," from usus, "use" (from uti, "to use"). Originally it meant charging any interest at all, which medieval church law condemned; as lending became normal, the word narrowed to interest that is excessive or predatory.
noun · /YOO-zhuh-ree/
The practice of lending money at an unreasonably high or exploitative rate of interest.
What it names
It is the word for lending that traps rather than helps — the payday loan whose rate makes the debt nearly impossible to escape.
Example
The storefront lender’s four-hundred-percent annual rate was usury in all but name.
Related idea
A dividend rewards owning a share of a business; usury is what turns lending itself into exploitation.