Decorates with frosting (4)
I believe the answer is:
ices
'decorates with frosting' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ices that I've seen before include "ecorates with frosting" , "Frozen sweets" , "they may be held in the summer" , "Frozen desserts" , "Decorates cakes with frosting" .)