Minuscule margin (4)
I believe the answer is:
nose
'minuscule margin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nose that I've seen before include "Bouquet of wine; beak" , "Deserving blame" , "Flair (for wine)" , "Olfactory organ" , "blow it!" .)