Definition of darnedest in US English:

darnedest

adjective

North American
informal
  • Used to emphasize the surprising nature of something.

    ‘people say the darnedest things when they've got an audience’

Phrases

  • do (or try) one's darnedest

    • informal Do or try one's utmost.

      ‘the director does his darnedest to manufacture tension and suspense in the film’

Origin

Mid 19th century: euphemism for damnedest.

Pronunciation

darnedest

/ˈdɑrndəst//ˈdärndəst/