Long-standing rivalry (4)
I believe the answer is:
feud
(Other definitions for feud that I've seen before include "Conflict" , "Squabble" , "Lasting hostility between people or groups" , "Prolonged quarrel" , "Quarrel; spat" .)
I believe the answer is:
feud
(Other definitions for feud that I've seen before include "Conflict" , "Squabble" , "Lasting hostility between people or groups" , "Prolonged quarrel" , "Quarrel; spat" .)