Tolerate the wrong idea about Brideshead (5)
I believe the answer is:
abide
'tolerate' is the definition.
('abide' can be a synonym of 'tolerate')
'the wrong idea about brideshead' is the wordplay.
'the wrong' is an anagram indicator.
'about' indicates putting letters inside.
'brideshead' becomes 'b' (head letter of 'brides').
'idea' with letters rearranged gives 'aide'.
'aide' enclosing 'b' is 'ABIDE'.
(Other definitions for abide that I've seen before include "live in the past?" , "'. . . . . with me, fast falls the eventide'" , "Stomach" , "Tolerate - dwell" , "Put up with" .)