Spread of British hatred is grotesque (7)
I believe the answer is:
breadth
'spread' is the definition.
(thesaurus)
'british hatred is grotesque' is the wordplay.
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'is grotesque' indicates an anagram.
'hatred' with letters rearranged gives 'readth'.
'b'+'readth'='BREADTH'
'of' is the link.
(Other definitions for breadth that I've seen before include "Measurement from side to side" , "generosity of mind" , "Width, thickness" , "Distance from side to side" , "Lateral extent" .)