Fair play from English, somewhat reduced before close of play (6)
I believe the answer is:
equity
'fair play' is the definition.
(thesaurus)
'english somewhat reduced before close of play' is the wordplay.
'english' becomes 'e' (abbreviation).
'somewhat' becomes 'quite' (I've seen this before).
'reduced' means to remove the last letter.
'before close of play' becomes 'y' (I've seen this in other clues).
'quite' with its final letter taken off is 'quit'.
'e'+'quit'+'y'='EQUITY'
'from' is the link.
(Other definitions for equity that I've seen before include "Fair play - actors' union" , "Fairness, impartial treatment" , "Fairness or impartiality" , "Even-handedness" , "Group of performers" .)