Head wrestling with quiet ref cut in (7)
I believe the answer is:
supremo
'head' is the definition.
(I have seen 'Overall head ' mean 'supremo' so perhaps 'head' could also mean 'supremo')
'wrestling with quiet ref cut in' is the wordplay.
'wrestling' becomes 'sumo' (I've seen this before).
'with' is an insertion indicator.
'quiet' becomes 'p' (music symbol for 'piano', ie soft or quiet).
'cut' means to remove the last letter.
'in' means one lot of letters goes inside another.
'sumo' enclosing 'p' is 'supmo'.
'ref' with its final letter taken away is 're'.
'supmo' enclosing 're' is 'SUPREMO'.
(Other definitions for supremo that I've seen before include "Leader with unlimited powers" , "Person in overall authority" , "Big fish" , "Person in overall charge, really the top man" , "Big cheese, head honcho" .)