He makes unpredictable, arbitrary decisions.
他做的决定难以预料，主观武断。
Arbitrary arrests and detention without trial were common.
随意逮捕和拘留屡见不鲜。
The court became notorious for its arbitrary methods and severe punishments.
该法庭因其独断的方式和严厉的制裁而声名狼藉。
You can make an arbitrary choice.
你可以随便做选择。
The old man became increasingly prejudiced, arbitrary, and senile.
他越来越变成一个偏见、固执和独断的老人。