Definitions of rash:

• noun:   a series of unexpected and unpleasant occurrences

  Example: "A rash of bank robberies"

• noun:   any red eruption of the skin
• adjective:   imprudently incurring risk

  Example: "Do something rash that he will forever repent- George Meredith"

• adjective:   marked by unthinking boldness; with defiant disregard for danger or consequences

  Example: "A rash attempt to climb the World Trade Center"

• name:  A surname (rare: 1 in 25000 families; popularity rank in the U.S.: #3216)