Source : Free On-Line Dictionary of Computing

drop-outs
     
        1. A variety of "power glitch" (see {glitch}); momentary 0
        voltage on the electrical mains.
     
        2. Missing characters in typed input due to software
        malfunction or system saturation (one cause of such behaviour
        under {Unix} when a bad connection to a modem swamps the
        processor with spurious character interrupts; see {screaming
        tty}).
     
        3. Mental glitches; used as a way of describing those
        occasions when the mind just seems to shut down for a couple
        of beats.  See {glitch}, {fried}.
     
        [{Jargon File}]
     
        (2001-02-22)