I
n.
1) a bitter; bloody; violent clash
2) a clash between (there was a violent clash between the two rivals)
3) a clash with (a clash with the police)
II
v.
1) (D; intr.) ('to argue') to clash over
2) (D; intr.) ('to struggle') to clash with (the demonstrators clashed with the police)
3) (D; intr.) ('not to match') to clash with (red clashes with green)