So near sports ground (6)
I believe the answer is:
reason
'ground' is the definition.
(synonyms)
'so near sports' is the wordplay.
'sports' is an anagram indicator (I've seen 'sporting' mean this).
'so'+'near'='sonear'
'sonear' is an anagram of 'REASON'.
(Other definitions for reason that I've seen before include "Reach logical conclusions" , "Motive or right thinking" , "logical argument" , "Deduce" , "Cause; mind's power" .)