Touchback is a term used in sports, particularly in American football and rugby. It refers to a play that results in the ball becoming dead behind the goal line or end zone. However, there are several synonyms for touchback that can be used interchangeably, such as touchdown down, goalback, dead ball, and end line. These terms are often used by commentators and sports enthusiasts alike to describe a play where the ball is kicked or carried into the end zone, but does not result in a score. Regardless of which synonym is used, the meaning remains the same in the context of sports.