General Adjectives:
* Conflicting: This describes a situation where things are incompatible or opposed. "The two groups had conflicting views."
* Discordant: This suggests a lack of harmony or agreement. "The music was discordant and jarring."
* Contentious: This suggests a strong disagreement or argument. "The issue of immigration is a contentious one."
More Specific Adjectives:
* Violent: If the clash involves physical violence. "The two gangs had a violent clash."
* Explosive: If the clash is sudden and intense. "There was an explosive clash between the protesters and the police."
* Dramatic: If the clash is impactful and noteworthy. "The two candidates had a dramatic clash during the debate."
* Head-on: If the clash is direct and forceful. "The two cars had a head-on clash."
The best adjective to use will depend on the specific context and the intended meaning.