chaotic

形容词 chaotic:

1. lacking a visible order or organization
   同义词：helter-skelter
2. completely unordered and unpredictable and confusing
   同义词：disorderly
3. of or relating to a sensitive dependence on initial conditions

1. With no one to keep order the situation in the classroom was chaotic.
   因无人维持秩序，教室里一片混乱。