If you describe someone or something as unpredictable, you mean that you cannot tell what they are going to do or how they are going to behave.
changeable
He is utterly unpredictable.
他这个人完全让人捉摸不透。
In macular surgery, outcomes are unpredictable.
黄斑手术的结果不好预测。
Adding more elements into the equation might have unpredictable consequences.
在此平衡关系中加入更多因素可能会产生难以预测的后果。
an unpredictable work environment.
一个不稳定的工作环境。