To masturbate (especially of women).
To cheat; to swindle.
To waste time.
To molest.
To totter, like a child learning to walk; to daddle.
To manipulate a value at the level of individual bits (binary digits).
A meaningless word used when singing a tune or indicating a rhythm.
The penis.
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.
To be unfaithful to one's (sexual) partner.
To double-cross.
On two occasions; twice.