Turn to a snack (4)
I believe the answer is:
roll
'turn' is the definition.
(roll is a kind of turn)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for roll that I've seen before include "Move by turning over" , "Bread - list - sway" , "Small round piece of bread" , "Furl" , "Bakery product" .)