What is "walk-off"

walk-off \walk"-off`\, a. (Baseball) Game-ending and game-winning; such as to end the game immediately, and allow the players to walk off the field; -- of hits, especially home runs, which occur in the last half of the ninth or a later inning, which put the home team ahead of the visiting team and thereby end the game immediatey. This occurs in baseball because, when the last half of the ninth inning arrives, if the home team (which bats last) is already ahead in the score the last half of that inning is not played, the winner of the game having already been decided. Likewise, as soon as the home team gets ahead in the score after the visiting team has batted in the ninth inning, the game is ended. [Baseball jargon]

Curtis's homer over the left-center-field fence beat the Braves and was the first walk-off homer by a Yankee in the World Series since Mickey Mantle slugged one against the St. Louis Cardinals in game 3 in 1964.
--Jack Curry (New York Times, Oct. 28, 1999 p. D4)

There are so many people in here who are happy for Chad. We know what he's been through. Those hits could make Chad Curtis's whole year. When you hit a walk-off homer in the World Series, that's something he's going to remember for a long time.
--Paul O'Neill (the Yankee outfielder, quoted by Jack Curry in the New York Times, Oct. 27, 1999 p. D4)

a. (context baseball of a hit English) That drive in a run that ends a game. alt. (context baseball of a hit English) That drive in a run that ends a game. n. 1 A prisoner who escapes custody without violence by taking advantage of the opportunity provided by negligence or distraction of guards. 2 A walkout. 3 (context baseball English) Any event or action in the bottom of the last inning of a game that scores a run and thereby ends the game with a victory to the team at bat.

Walk-off may refer to:

• an event in a sporting event where the game winning score immediately ends the game, such as a walk-off home run in baseball, a touchdown or field goal that's scored when there's no time left on the clock or during the overtime period, or a game-winning goal that's scored in association football during extra time.
• a political or economic protest
  • Cummeragunja walk-off by aboriginal Australians in 1939 in New South Wales
  • Wave Hill walk-off in 1966 in the Northern Territory of Australia
• The Walk-Offs, a 1920 American silent comedy film directed by Herbert Blaché