did·dle / ˈdidl/ • v. inf. 1. [tr.] (usu. be diddled) cheat or swindle (someone) so as to deprive them of something: he thought he'd been diddled out of his change. ∎ deliberately falsify (something): he diddled his income tax returns.2. [intr.] inf. pass time aimlessly or unproductively: why diddle around with slow costly tests? ∎ (diddle with) play or mess with: he diddled with the graphics on his computer.3. [tr.] vulgar slang have sexual intercourse with (someone).DERIVATIVES: did·dler n.