a.

1. 草率從事的，輕率的
   Don't make a rash decision.

   別倉促作出決定。

2. 急躁的，魯莽的
   It is rash to cross the street without looking both ways.

   不朝兩邊看看就穿馬路是莽撞的。

n.

1. 疹，疹子[C]
   The girl broke out in a rash today.

   今天，這女孩身上出了疹子。

2. 一下子爆發的一連串（多指不愉快的事物）[S][（+of）]
   Students made a rash of complaints.

   學生們發出一片抱怨聲。

adj.

n.

1. an area of redness and spots on the skin.
2. an unwelcome series of things happening within a short space of time:
   a rash of strikes.