Said to use wine in cooking for a particular purpose (2,3)
I believe the answer is:
ad hoc
'a particular purpose' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for ad hoc that I've seen before include "(Of committee) formed for a single purpose" , "For a specific purpose - latin phrase" , "'Improvised or impromptu (2,3)'" , "Latin notation - for a specific purpose" , "not in general practice" .)