Eat like lightning (4)
I believe the answer is:
bolt
This clue is a double definition.
'eat' is the first definition.
(I know that bolt is the is a more specific form of the action of eat.)
'lightning' is the second definition.
(I know that bolt is a type of lightning)
'like' is the link.
(Other definitions for bolt that I've seen before include "eat food quickly and > lock up" , "Runner" , "wolf" , "Leg it < and consume apace" , "It makes fast" .)