manipulate, as in a nervous or unconscious manner
To trifle with something.
To tinker is defined as to play around with something, or to try to change or fix it.
To do something superficially, not seriously
To change so as to be suitable to or conform with something else:
Find another word for fiddle-with. In this page you can discover 6 synonyms, antonyms, idiomatic expressions, and related words for fiddle-with, like: tinker with, tinker, play-with, twiddle, dabble and adjust.