The term "Extra" has multiple meanings depending on its context.
1) In a general sense, an extra is someone or something that goes beyond what is usual or expected; additional or supplementary. For example, "I need some extra money to pay for the bills."
2) In film and television production, an extra is an actor who appears in a scene as an unspecified character, often in the background of shots. They are not part of the main cast but help to create realistic scenes by adding more people or extras to the shot.
3) In sports, an extra can refer to additional time played to make up for time lost due to a delay, such as an injury or a timeout taken by one team. For example, "The game went into extra time because of the delayed start."