Example: "One of the tires developed a leak"
Example: "He had to take a leak"
Example: "They tried to stop the escape of gas from the damaged pipe"
Example: "The news was leaked to the paper"
Example: "Water leaked out of the can into the backpack"
Example: "The container leaked gasoline"
Of a document, etc, produced by a company or organization, intended to be confidential but having been released to the public or the press.