usury
noun [ U ]
formal disapproving uk/ˈjuːzjʊri/ us/-ʒɚI/the lending of money at extremely high interest rates:
The payday loans, exempt from usury laws, carry an annual interest rate of 390%.
usurer
noun [ C ] uk/ˈjuːzjʊrər/ us/-ʒɚə˞/
a usurer who charged extortionate rates of interest
usurious
adjective uk/juːˈzjʊəriəs/ us/juːˈʒʊri-/
a usurious rate