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

breakpoint

    A point in a program that, when reached, triggers
   some special behavior useful to the process of debugging;
   generally, breakpoints are used to either pause program
   execution, and/or dump the values of some or all of the
   program variables.  Breakpoints may be part of the program
   itself; or they may be set by the programmer as part of an
   interactive session with a debugging tool for scrutinizing the
   program's execution.

   (1999-06-07)