Rash/ræʃ/ Definition 1 of 3Pro Tip 1/3Impulsivity Connotation Rash, when describing a person's actions, implies lack of careful thought or impulsive behavior. Ignoring the risks, he made a rash investment. Pro Tip 2/3Negative Outcome Using 'rash' usually suggests that the outcome of the action was not good. Her rash decision led to a failed project. Pro Tip 3/3Cautionary Advice The word 'rash' can be used to advise someone to think carefully before acting. Don't be rash - weigh all your options first.