from
The Free On-line Dictionary of Computing (8 July 2008)
breakpoint
<programming> 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)