Reach for old wine (6)
I believe the answer is:
extent
'reach' is the definition.
(I've seen this in another clue)
'old wine' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'wine' becomes 'tent' (type of Spanish wine).
'ex'+'tent'='EXTENT'
'for' acts as a link.
(Other definitions for extent that I've seen before include "Scope, area" , "Range or scope of something" , "Compass, scope" , "A cake; last word of Macbeth" , "Area; size" .)