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

wall time
 n.

    (also wall clock time)

    1. ?Real world? time (what the clock on the wall shows), as opposed to the
    system clock's idea of time.

    2. The real running time of a program, as opposed to the number of ticks
    required to execute it (on a timesharing system these always differ, as no
    one program gets all the ticks, and on multiprocessor systems with good
    thread support one may get more processor time than real time).


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

wall time

   (Or "wall clock time") 1. "Real world" time (what the clock on
   the wall shows), as opposed to the system clock's idea of
   time.

   2. The real running time of a program, as opposed to the
   number of ticks required to execute it (on a time-sharing
   system these always differ, as no one program gets all the
   ticks, and on multiprocessor systems with good thread support
   one may get more processor time than real time).

   [Jargon File]