The word "rash" can refer to two primary meanings. First, it is an adjective that describes a behavior that is made quickly and without careful thought, often leading to negative outcomes, such as taking a rash decision. Second, it can be a noun that refers to a sudden outbreak of red spots or irritation on the skin, often caused by an allergic reaction or illness.
The word "rash" originates from the Middle English term "rasche," which meant "hasty" or "quick." It comes from the Old Norse word "ræskr," which means "quick" or "eager." Over time, it evolved further to encompass both the impulsive behavior and the dermatological condition.