Bear's paunch (7)
I believe the answer is:
stomach
This clue is a double definition.
'bear's' is the first definition.
(both can mean to endure or tolerate)
'paunch' is the second definition.
(paunch can mean one's stomach)
(Other definitions for stomach that I've seen before include "Bear - belly" , "Bag-like part of the alimentary canal" , "Internal organ" , "Breadbasket (informal)" , "Could Mac host this organ?" .)