Mistress caught at the right moment outside wine store (9)
I believe the answer is:
concubine
'mistress' is the definition.
(concubine is a kind of mistress)
'caught at the right moment outside wine store' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'at the right moment' becomes 'oncue' (I've seen this in another clue).
'outside' is an insertion indicator.
'wine store' becomes 'bin' (stand for storing wine bottles).
'oncue' going around 'bin' is 'oncubine'.
'c'+'oncubine'='CONCUBINE'
(Another definition for concubine that I've seen is " Unmarried woman cohabiting with a man - secondary wife".)