to make small changes to something to try to make it work

Stop fiddling about with your hair - it looks fine. 别再摆弄你的头发了，它看起来挺好的。

Someone's been fiddling around with my computer! 有人动过我的电脑！

to touch or move things with your fingers because you are nervous or bored

He was just fiddling around with the things on his desk. 他只是无聊地摆弄着他桌子上的东西。