Definition of Dead Rubber

What is the meaning of the term Dead Rubber when it comes to sports?

A Dead Rubber is used to describe a match in a series that has already been decided. In soccer for example, if a team has a large advantage from the first leg match in a tournament, the second leg match is called Dead Rubber, as the chances of the losing team to overturn the deficit are minimal.

A real life recent example would be a match between Manchester City and FC Basel in the UEFA Champions League Round of 16, where City have a 4-0 advantage from the first leg. The chances of FC Basel coming to the Etihad Stadium, where Manchester City are undefeated during the entire 2017/18 season, and winning 4-0 or 5-1 are very slim. This match is called a Dead Rubber match.

Another example, this time in the sport of tennis, would be the fifth and last Davis Cup match, when the score is 3-1 and one nation has already secured advancement to the next round of the tournament. Regardless of what happens in the fifth match, it makes no difference. A such match is called Dead Rubber.