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

time-sharing

    (Or "timesharing") An operating system
   feature allowing several users to run several tasks
   concurrently on one processor, or in parallel on many
   processors, usually providing each user with his own terminal
   for input and output.  time-sharing is multi-user
   multitasking.

   (2009-11-23)