Pastry (3)
I believe the answer is:
pie
'pastry' is the definition.
(I know that Pie is a type of pastry)
This is all the clue.
(Other definitions for pie that I've seen before include "where blackbirds sang" , "Covered flan" , "In the sky, it's a hopeless idea" , "Pastry product" , "Filled pastry" .)