c.1540, "to trifle," of unknown origin; of the fingers, first recorded 1676. Fig. phrase twiddle one's thumbs "have nothing to do" is recorded from 1846; to twirl one's thumbs in the same sense is recorded from 1816.
The tilde, a diacritical mark used especially in Spanish
To change something in a small way; tweak(1980s+ Computer)
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source
twiddle in Technology
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)