Masticate (3)
'masticate' is the definition.
(synonyms)
This is all the clue.
(Other definitions for chew that I've seen before include "Masticate, grind between teeth" , "work with canines" , "bit of tobacco" , "Process food" , "Try to eat" .)
(Other definitions for eat that I've seen before include "Ingest" , "Break bread" , "Worry" , "Bit, chew and swallow" , "Devour" .)