n. 1. [techspeak] On some processors, an attempt to calculate a result too large for a register to hold causes a particular flag called an overflow bit to be set.
2. Hackers use the term of human thought too.
"Well, the Ada description was baroque all right, but I could hack it OK until they got to the exception handling... that set my overflow bit."
3. The hypothetical bit that will be set if a hacker doesn't get to make a trip to the Room of Porcelain Fixtures:
"I'd better process an internal interrupt before the overflow bit gets set".