Light snack (4)
I believe the answer is:
nosh
'light snack' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for nosh that I've seen before include "Food (sl.)" , "Eat (slang) -- food (slang)" , "Slangy food or meal" , "eating this?" , "chow" .)