Bite at persistently (4)
I believe the answer is:
gnaw
(Other definitions for gnaw that I've seen before include "Chew and grind down" , "Chew away at" , "Nibble like a rodent" , "Bite persistently, grind" , "Chew or crunch at" .)
I believe the answer is:
gnaw
(Other definitions for gnaw that I've seen before include "Chew and grind down" , "Chew away at" , "Nibble like a rodent" , "Bite persistently, grind" , "Chew or crunch at" .)