Moving so near ground (6)
I believe the answer is:
reason
'ground' is the definition.
(I know that ground can be written as reason)
'moving so near' is the wordplay.
'moving' indicates an anagram (letters are moved around).
'so'+'near'='sonear'
'sonear' is an anagram of 'REASON'.
(Other definitions for reason that I've seen before include "Explanation or justification" , "issue" , "Cause - logic" , "Justification needed" , "The right exercise of the mind" .)