Definition of the penny dropped in English:

the penny dropped

phrase

British
informal
  • Used to indicate that someone has finally realized something:

    ‘I was about to ask Jack who it was, when the penny suddenly dropped’
    • ‘I was treated for depression for two years before the penny dropped.’
    • ‘It was about that time that I noticed the stubble on her co-worker's chin, and again the penny dropped.’
    • ‘Shortly after my son was born, the penny dropped that in all probability, one day I would be some girl's mother-in-law.’
    • ‘Then the penny dropped and the fun began as we tried to translate all the weird, wonderful phonetic spellings of the dishes on offer.’
    • ‘Then when I called her up the penny dropped that this was the Kathy I had known at school.’
    • ‘Frequently we would find ourselves in situations where we were being delayed for hours on end, until the penny dropped and it finally became clear that the only way to move on was by crossing palms with silver.’
    • ‘Finally the penny dropped - the thought of being embarrassed in front of the elite coaches and players of English rugby frightened me to death.’
    • ‘Suddenly the penny dropped when some of the more familiar names were just a bit too familiar.’
    • ‘Hasn't the penny dropped yet for these clever customers?’
    • ‘At some time over the past few weeks, the penny dropped.’