Sandwich (6)
I believe the answer is:
sarnie
'sandwich' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sarnie that I've seen before include "Sandwich (slang)" , "Familiar form of snack" , "Popular bread-based snack (colloq)" , "Sandwich (informal)" , "Bread and filling snack (informal)" .)