A slang term for ecstacy pills. Can also be used to describe the state of mind of a person who's high on pills('Diddled'). Any arrangements on this is acceptable, e.g 'diddly-doo', 'dids', 'diddlered'.
Mark : 'How're those diddles doing for ya?'
James: 'Man, i'm fucking diddled of my face man. Could do with another diddly-doo though if you've got one?'
Mark: 'Sorry bro, all out of dids, you sank them all you diddly twat'
On guys it is the front part of the underarm used in conjuction with the arm and torso to form a pillow for other people to make them feel safe and comforted.