Close, close, close (6)
I believe the answer is:
nearby
'close' is the definition.
('nearby' can be similar in meaning to 'close')
'close close' is the wordplay.
'close' becomes 'near' ('near' can be a synonym of 'close').
'close' becomes 'by' (I've seen this in other clues).
'near'+'by'='NEARBY'
(Other definitions for nearby that I've seen before include "Locally" , "A short distance away" , "somewhere close" , "Close at hand, not far away" , "In the vicinity" .)