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

uniprocessor

    (From "uni" - one) A computer with a single
   central processing unit, in contrast to a parallel
   processor.  Most personal computers are currently (March
   1997) uniprocessors.  Some more expensive computers, typically
   servers, have multiple processors to provide increased
   throughput.

   See also symmetric multiprocessor and massively parallel
   processor.

   (1997-03-23)