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.
A kind of substance.
Matter made up of normal particles, not antiparticles.
Aristotelian: undeveloped potentiality subject to change and development; formlessness. Matter receives form, and becomes substance.
An affair, condition, or subject, especially one of concern or (especially when preceded by the) one that is problematic.
The basic structural component of the universe, usually having mass and volume.
An approximate amount or extent.
Printed material, especially in books or magazines.
To be important.
To care about, to mind; to find important.