Regular fee one ground typically slashed (10,4)
I believe the answer is:
peppercorn rent
'regular fee one' is the definition.
The definition suggests a singular noun which matches the answer.
'ground typically slashed' is the wordplay.
I cannot quite see how this works, but
'slashed' could be 'rent' (I've seen this before) and 'rent' is located in the answer.
The remaining letters 'peppercorn' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for peppercorn rent that I've seen before include "nominal charge" , "cost of cheap accommodation" .)