Mostly praise corporation over being member-owned (6)
I believe the answer is:
mutual
'member-owned' is the definition.
(financial term)
'mostly praise corporation over' is the wordplay.
'mostly' means to remove the last letter.
'praise' becomes 'laud' (lauding is a kind of praising).
'corporation' becomes 'tum' (I've seen this before).
'over' says the letters should be written in reverse.
'laud' with its last letter removed is 'lau'.
'lau'+'tum'='lautum'
'lautum' in reverse letter order is 'MUTUAL'.
'being' acts as a link.
(Other definitions for mutual that I've seen before include "like Dickens's friend?" , "Joint < commonly" , "Given and returned" , "Felt by each towards the other, like friendship" , "Reciprocal or shared, like friendship" .)