Bear's appetite (7)
I believe the answer is:
stomach
This clue is a double definition.
'bear's' is the first definition.
('stomach' can be a synonym of 'bear')
'appetite' is the second definition.
(stomach is a kind of appetite)
(Other definitions for stomach that I've seen before include "Could Mac host this organ?" , "Appetite for food" , "Put up with" , "Tolerate; appetite" , "Digestive organ" .)