Rival firm getting more pruned, holding little in France (10)
I believe the answer is:
competitor
'little in france' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'rival firm getting more pruned holding' is the wordplay.
'rival' becomes 'petit' (I am not sure about this - if you are sure you should believe this answer much more).
'firm' becomes 'co' (abbreviation for company).
'getting' means one lot of letters go next to another.
'pruned' means to remove the last letter.
'holding' is an insertion indicator.
'more' with its final letter taken away is 'mor'.
'co'+'mor'='comor'
'petit' inserted inside 'comor' is 'COMPETITOR'.
Can you help me to learn more?
(Other definitions for competitor that I've seen before include "Sporting contest entrant" , "rival trader?" .)