Clash, discord (8)
I believe the answer is:
conflict
I believe this clue is a double definition.
'clash' is the first definition.
(I know that clash is a kind of conflict)
'discord' is the second definition.
(I've seen this before)
(Other definitions for conflict that I've seen before include "A battle or struggle" , "Strife and struggle" , "Serious disagreement" , "Battle - be incompatible" , "Discord, contention" .)