Eat constantly - from scratch? (5)
I believe the answer is:
graze
I believe this is a double definition.
'eat constantly' is the first definition.
'scratch?' is the second definition.
(graze is a kind of scratch)
'from' is the link.
(Other definitions for graze that I've seen before include "Bark (shin)" , "Eat grass, or snack" , "Abrasion" , "Browse; scratch" , "chomp on pasture" .)