Economise when importing old wine (5)
I believe the answer is:
soave
'wine' is the definition.
(I know that Soave is a type of white wine)
'economise when importing old' is the wordplay.
'economise' becomes 'save' (saving is a kind of economising).
'when importing' indicates putting letters inside.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'save' enclosing 'o' is 'SOAVE'.
(Other definitions for soave that I've seen before include "White wine from NE Italy" , "Drink" , "Italian dry white wine" , "Italian wine region" , "Dry white wine from Verona" .)