Chewed section (3)
I believe the answer is:
bit
This clue is a double definition.
'chewed' is the first definition.
'section' is the second definition.
(both can mean part)
(Other definitions for bit that I've seen before include "Snaffle - small piece" , "gripped" , "Sank teeth in" , "The boring-piece of a drill" , "Morsel" .)