Stop entertaining frightfully rude bore (7)
I believe the answer is:
endured
'bore' is the definition.
(bear can mean to endure)
'stop entertaining frightfully rude' is the wordplay.
'stop' becomes 'end' (synonyms).
'entertaining' indicates putting letters inside (inviting in, as for dinner).
'frightfully' indicates anagramming the letters (I've seen this in other clues).
'rude' anagrammed gives 'dure'.
'end' placed around 'dure' is 'ENDURED'.
(Other definitions for endured that I've seen before include "Red nude (anag.)" , "Put up with something" , "Bore; put up with" , "Patiently suffered" , "Bore or tolerated" .)