Menu item’s recent re-emergence, somewhat reduced (6)
I believe the answer is:
entree
'menu item's' is the definition.
(course on a menu)
'recent re-emergence somewhat reduced' is the wordplay.
'somewhat reduced' says the answer is hidden in the clue.
'ENTREE' is hidden within 'recent re emergence'.
(Other definitions for entree that I've seen before include "The right to be admitted" , "Introduction" , "Right of entrance for a dish?" , "Dish allowing one to go in?" , "Principal dish and right to enter" .)