He takes more than usual interest in his work (6)
I believe the answer is:
usurer
This might be a double definition.
'he' is the first definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'more than usual interest in his work' is the second definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'takes' acts as a link.
Can you help me to learn more?
(Other definitions for usurer that I've seen before include "Shylock, for example" , "source of interest" , "Person taking a lot of interest" , "Extortionist" , "Extortionate lender of money" .)