Meaning: to play a violin:
* The musician fidddled a lively tune on his violin.
* She spent hours fiddling away on her favorite fiddle.
Meaning: to tinker with something, often in a playful way:
* He was fiddling with the radio antenna, trying to get a better signal.
* Don't fiddle with the settings on your computer, you might mess it up!
Meaning: to cheat or manipulate something:
* The politician was accused of fiddling the election results.
* He was caught fiddling the company books to hide the losses.
Meaning: to act nervously or fussily:
* She fidddled with her necklace, trying to hide her nervousness.
* He fidddled with the pen, unable to focus on the important task.
Let me know if you'd like to see more examples!