Expert away probing wine store (6)
I believe the answer is:
boffin
'expert' is the definition.
(boffin means an expert)
'away probing wine store' is the wordplay.
'away' becomes 'off' (synonyms).
'probing' is an insertion indicator (probe can mean to poke or prod into).
'wine store' becomes 'bin' (stand for storing wine bottles).
'off' going inside 'bin' is 'BOFFIN'.
(Other definitions for boffin that I've seen before include "(Government) scientist" , "Technical expert" , "Military scientist" , "Back-room boy" , "Scientist (in the back room?)" .)