Double-dog action is a term used to describe an extreme form of daring or risk-taking. It is derived from the phrase 'double-dog DARE, ' which is a challenge issued to someone to do something that is considered dangerous or difficult. The term 'DARE' is often used in this context, and it is a four-letter word. Double-dog action is usually associated with activities such as skydiving, bungee jumping, and other extreme sports.