He takes great interest in your need for cash (6)
I believe the answer is:
usurer
'he takes great interest in your need for cash' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
This is the entire clue.
Can you help me to learn more?
(Other definitions for usurer that I've seen before include "Grasping money-lender" , "Person who charges excessive interest on loan" , "Moneylender who charges excessive rates of interest" , "Unscrupulous lender" , "Businessman taking a lot of interest" .)