Item of fast food (3,3)
I believe the answer is:
hot dog
'item of fast food' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for hot dog that I've seen before include "Long roll containing sausage" , "Sausage in a roll - acrobatic skier" , "One panting" , "Sausage in a bun" , "'Frankfurter in a bun (3,3)'" .)