Twiddle (verb)

To play idly with something, or to move something in a nervous or absent-minded way.

Origin:

Early 17th century (in the sense "fiddle with"): perhaps imitative of the sound of fingers twirling something.

Examples:

1. He twiddled his thumbs while waiting for the meeting to start.
2. She twiddled her hair while thinking about what to say next.
3. The child twiddled the knobs on the radio until he found a good station.
4. He twiddled with the pen cap during the lecture.
5. She twiddled her ring nervously while she waited for the results.