1. The tilde character. 2. (To make) a small or insignificant change. E.g. twiddling a program often fixes one bug and generates several new ones (see also shotgun debugging). Bits are often twiddled. Twiddling a switch or knob implies much less sense of purpose than toggling or tweaking it see frobnicate. Bit twiddling connotes aimlessness, and at best doesn' t specify what you' re doing to the bit to "toggle a bit" has a more specific meaning. [Jargon File] (1995-01-31)
