Make me pay a penalty in rent for an improvement (10)
I believe the answer is:
refinement
'for an improvement' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for refinement that I've seen before include "Polish" , "Improvement; elegance" , "Elegance, sophistication" , "Cultivation" , "culture" .)