A theoretical construct or device with known input and output characteristics but unknown method of operation.
A flight recorder; the brightly colored cockpit voice recorders and flight data recorders in an aircraft designed to aid in determining the cause of an accident.
A device used in phreaking that prevents the calling party from being billed for the call placed.
A type of theater characterized by a lack of decoration or complex mechanisms.
Any similar device on motor vehicles, such as rail event recorders and ship trip recorders.
To focus on the inputs and outputs without worrying about the internal complexity.
Practice of these particular games, or techniques used in them.
American football: a game played on a field of 100 yards long and 53 1/3 yards wide in which two teams of 11 players attempt to get an ovoid ball to the end of each other's territory.
rugby league.
The leather briefcase containing classified nuclear war plans which is always near the US President.
A sport played on foot in which teams attempt to get a ball into a goal or zone defended by the other team.
rugby union.
Australian rules football.
The ball used in any game called "football".
Canadian football: a game played on a field of 110 yards long and 65 yards wide in which two teams of 12 players attempt to get an ovoid ball to the end of each other's territory.
Association football: a game in which two teams each contend to get a round ball into the other team's goal primarily by kicking the ball. Known as soccer in Canada, the United States, Australia, and New Zealand.
Gaelic football: a field game played with similar rules to hurling, but using hands and feet rather than a stick, and a ball, similar to, yet smaller than a soccer ball.
An item of discussion, particularly in a back-and-forth manner
To play football.