Member inspiring a posh English sporting association (6)
I believe the answer is:
league
'sporting association' is the definition.
(eg a football league)
'member inspiring a posh english' is the wordplay.
'member' becomes 'leg' (member can mean a limb).
'inspiring' is an insertion indicator.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'english' becomes 'E' (abbreviation).
'leg' enclosing 'a' is 'leag'.
'leag'+'u'+'e'='LEAGUE'
(Other definitions for league that I've seen before include "Group in football" , "Alliance, association" , "Federation" , "Old measure of distance, about 3 miles" , "Old distance measure of about three miles" .)