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

processor time
CPU time

    The amount of time a process takes to run, given
   that it has exclusive and uninterrupted use of the CPU.
   Note that in a modern computer, this would be very unusual,
   and so the processor time calculation for most processes
   involves adding up all the small amounts of time the CPU
   actually spends on the process.

   Some systems break processor time down into user time and
   system time.

   Compare wall clock time.

   (1998-03-13)