A violin. A member of the violin family. Nautical A guardrail used on a table during rough weather to prevent things from slipping off. Informal Nonsensical, trifling matters: "There are things that are important/beyond all this fiddle\u201d ( Marianne Moore). The act or an instance of cheating or swindling; a fraud. To play a violin. To move one's fingers or hands in a nervous fashion. To occupy oneself in an aimless or desultory way: liked to fiddle with all the knobs and dials. To meddle or tamper: a reporter who fiddled with the facts. To commit a fraud, especially to steal from one's employer. To play (a tune) on a violin. To cheat or swindle. To alter or falsify (accounts, for example) for dishonest gain. fiddle away To waste or squander: fiddled away the morning with unnecessary tasks.