President leaves a drop of red wine (5)
I believe the answer is:
macon
'wine' is the definition.
(I know that Macon is a type of wine)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for macon that I've seen before include "French wine district" , "Burgundian wine" , "Drink" , "A heavy Burgundy" , "Variety of Burgundy" .)