Large clubs put loner off (9)
I believe the answer is:
corpulent
'large' is the definition.
(thesaurus)
'clubs put loner off' is the wordplay.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'off' is an anagram indicator.
'put'+'loner'='putloner'
'putloner' with letters rearranged gives 'orpulent'.
'c'+'orpulent'='CORPULENT'
(Other definitions for corpulent that I've seen before include "Overweight" , "stout" , "bloated" , "Rotund, obese" , "Plump" .)