Usurer dream meaning is explained below using 2 different sources. Each interpretation is shown with its source.

Interpretation 1 — Gustavus Hindman Miller

To find yourself a usurer in your dreams, foretells that you will be treated with coldness by your associates, and your business will decline to your consternation.

If others are usurers, you will discard some former friend on account of treachery.

Source: Ten Thousand Dream Interpretation Author: Gustavus Hindman Miller

Interpretation 2 — Martha Clarke

Seeing a usurer in dreams warns of the possibility of earning a lot of money, although in a dishonest manner. In contrast, if you are the usurer, it foretells bad relations with your relatives and the possibility of enduring great humiliation. 
Source: The Big Dictionary of Dreams Author: Martha Clarke