diddly-squat

 
Pronunciation: /ˈdɪdlɪˌskwɒt/
(also doodly-squat)

pronoun

[usually with negative] informal
  • anything: Hiram didn’t care diddly-squat about what Darrel thought

Origin:

1960s: probably from US slang doodle 'excrement' + squat in the sense 'defecate'