In percussion, two consecutive notes played by the same hand (either RR or LL), similar to the drag, except that by convention diddles are played the same speed as the context in which they are placed
If someone diddles, they waste time and do not achieve anything. if Congress were to just diddle around and not take any action at all. to get money from someone by deceiving them diddle sb out of sth (Perhaps from Diddler, name of a character in a 19th-century English play)
deprive of by deceit; "He swindled me out of my inheritance"; "She defrauded the customers who trusted her"; "the cashier gypped me when he gave me too little change"
manipulate manually or in one's mind or imagination; "She played nervously with her wedding ring"; "Don't fiddle with the screws"; "He played with the idea of running for the Senate"