From Longman Dictionary of Contemporary Englishbe a fiddlebe a fiddle informalto be difficult to do and involve complicated movements of your hands This blouse is a bit of a fiddle to do up. → fiddle
Examples from the Corpus
be a fiddle• In the rear seat of the limousine Galvone was fiddling with his listening apparatus.• Gary was fiddling with his wedding band when his illumination came.• The following week he was fiddling with it in his lap at the start of the lesson.• I was fiddling around with a couple of tracks, trying various things.• I was fiddling blindly with files, my eyes full of terrible possibilities.• I was fiddling with the tuner, trying to get a station with news.• She was fiddling self-consciously with her wedding ring, twisting it around below her knuckle.