(1) (Comput) Descriptive of a computing system in which numerous terminal devices use a central computer concurrently for input, processing, and output functions. (2) (Man Sci) a. The apportionment of time-availability intervals of various items of equipment to complete several tasks by alternating and interlacing them. b. The use of a device for two or more purposes during the same overall time interval, accomplished by interspersing the separate actions in time