1. people who fidget with or manipulate objects aimlessly
2. people who adjust or turn controls, knobs, or dials

Examples

• The nervous twiddlers in the waiting room kept playing with their pens.
• Stop being such twiddlers and leave the radio settings alone.
• The children were constant twiddlers, always touching everything they could reach.
• As habitual twiddlers, they couldn’t sit still without something in their hands.
• The sound engineers were careful twiddlers of the mixing board controls.
• She watched the twiddlers adjust their instruments before the performance.