The Free On-line Dictionary of Computing (30 December 2018):

Nominal Semidestructor

    Slang for "National Semiconductor", found among
   other places in the 4.3BSD networking sources.  During the
   late 1970s to mid-1980s this company marketed a series of
   microprocessors including the National Semiconductor 16000
   and National Semiconductor 32000.  At one point early in the
   great microprocessor race, the specs on these chips made
   them look like serious competition for the rising Intel
   80x86 and Motorola 680x0 series.  Unfortunately, the actual
   parts were notoriously flaky and never implemented the full
   instruction set promised in their literature, apparently
   because the company couldn't get any of the mask steppings
   to work as designed.  They eventually sank without trace,
   joining the Zilog Z8000 and a few even more obscure
   also-rans in the graveyard of forgotten microprocessors.

   (1994-12-23)