rashes

That was a rash decision - you didn't think about the costs involved.

那个决定太轻率了——你没有考虑到这样做的代价。

I've got an itchy rash all over my chest.

我胸部出满了疹子，痒得要命。

There has been a rash of robberies/accidents/complaints in the last two months.

过去两个月中，突然发生很多起抢劫案／一下出了很多起事故／接二连三收到多起投诉。