New mascot hard to bear (7)
I believe the answer is:
stomach
'bear' is the definition.
(both can mean to endure or tolerate)
'new mascot hard' is the wordplay.
'new' indicates an anagram.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'mascot' anagrammed gives 'stomac'.
'stomac'+'h'='STOMACH'
'to' is the link.
(Other definitions for stomach that I've seen before include "Take" , "Corporation" , "Saclike organ" , "Food-processor" , "Endure, accept" .)