Definition of well I never! (or well I never did!) in US English:

well I never! (or well I never did!)

phrase

informal
  • Expressing great surprise or indignation.

    ‘Well I never—that's not like you!’
    • ‘There was the mother in her alpine attire staring rigidly ahead muttering ‘well I never!’’
    really?, is that so? is that a fact? you're joking! well i never, well i never did, go on, you don't say
    View synonyms