The Jargon File (version 4.4.7, 29 Dec 2003):

main loop
 n.

    The top-level control flow construct in an input- or event-driven program,
    the one which receives and acts or dispatches on the program's input. See
    also driver.


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

main loop

    The top-level control flow construct in an
   input- or event-driven program, the one which receives and
   acts or dispatches on the program's input events.

   See also driver.

   [Jargon File]

   (2004-03-12)