Dropout

1. In a communications system, a momentary loss of signal.

Note: Dropouts are usually caused by noise, propagation anomalies, or system malfunctions.

2. A failure to read properly a binary character from data storage.

Note: A dropout is usually caused by a defect in the storage medium or by a malfunction of the read mechanism.

3. In magnetic tape, disk, card, or drum systems, a recorded signal with an amplitude less than a predetermined percentage of a reference signal.

Source: from Federal Standard 1037C and from MIL-STD-188