(ca. 1983) Blend of Heisenberg + bug. Named for the Heisenberg uncertainty principle, which states very roughly that any attempt to measure the position of a subatomic particle will disrupt its movement, making it harder to predict.
heisenbug (plural heisenbugs)
- (computing) A software bug which fails to manifest itself during debugging; a problem that cannot be diagnosed in the debugger because it does not occur in that environment.