fiddle withphrasal verb
Definition of fiddle with
1 : to move or handle (something) with the hands or fingers in a nervous way She was nervously fiddling with her pencil as she waited for the test to start.
2 : to change or handle (something, such as the controls of a machine) in a way that shows one is not sure what to do He was fiddling with the controls of the television, trying to get it to work.
3 : to change (something) in a harmful or foolish way It became clear that someone had fiddled with the equipment.