Pickle from the south-west reportedly concerning (9)
I believe the answer is:
cornichon
'pickle from the south-west reportedly concerning' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'pickle from the south-west reportedly concerning' is the wordplay.
'pickle' becomes 'corn' (I've seen this in another clue).
'from the south' is a reversal indicator (in a down clue, letters go up).
'west reportedly' becomes 'hci' (I can't justify this - if you can you should believe this answer much more).
'concerning' becomes 'on' (both can mean 'in relation to').
'hci' written backwards gives 'ich'.
'corn'+'ich'+'on'='CORNICHON'
Can you help me to learn more?
(Another definition for cornichon that I've seen is " Type of small gherkin".)