Brandy (3-2-3)
'brandy' is the definition.
(eau de vie is a kind of brandy)
This is all the clue.
'brandy' is the definition.
(Cognac is an example)
This is the entire clue.
(Other definitions for cognac that I've seen before include "strong drink" , "High quality brandy" , "High-quality brandy" , "Brandy as for Napoleon (6)." , "warmer" .)