twiddle

v. (-ling) twirl, adjust, or play randomly or idly. n. Act of twiddling.  twiddle one's thumbs 1 make them rotate round each other. 2 have nothing to do.  twiddly adj. [probably imitative]

v. t. To touch lightly, or play with; to tweedle; to twirl; as, to twiddle one's thumbs; to twiddle a watch key.