black box
- an intricate, compact electronic component or device, such as a flight recorder, that can be quickly connected or disconnected as a unit
- anything having a complex function that can be observed but whose inner workings are mysterious or unknown
See black box in American Heritage Dictionary 4
nouna. A device or theoretical construct with known or specified performance characteristics but unknown or unspecified constituents and means of operation.
b. Something that is mysterious, especially as to function.
- See flight recorder.
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