Source : Webster's Revised Unabridged Dictionary (1913)

Diddle \Did"dle\, v. i. [Cf. {Daddle}.]
   To totter, as a child in walking. [Obs.] --Quarles.

Diddle \Did"dle\, v. t. [Perh. from AS. dyderian to deceive, the
   letter r being changed to l.]
   To cheat or overreach. [Colloq.] --Beaconsfield.

Source : WordNet®

diddle
     v 1: 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" [syn: {victimize}, {swindle}, {rook}, {goldbrick},
           {nobble}, {bunco}, {defraud}, {scam}, {mulct}, {gyp}, {con}]
     2: 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" [syn: {toy}, {fiddle}, {play}]

Source : Free On-Line Dictionary of Computing

diddle
     
        1. To work with or modify in a not particularly serious
        manner.  "I diddled a copy of {ADVENT} so it didn't
        double-space all the time."  "Let's diddle this piece of code
        and see if the problem goes away."
     
        See {tweak} and {twiddle}.
     
        2. The action or result of diddling.
     
        See also {tweak}, {twiddle}, {frob}.
     
        [{Jargon File}]
     
        (1995-01-31)