Definition of keep mum in English:

keep mum

phrase

informal
  • Remain silent, especially so as not to reveal a secret.

    • ‘he was keeping mum about a possible move to Canada’
    • ‘Think what you may; keeping mum gives me one secret more.’
    • ‘A good friend can keep mum about your deepest darkest secrets.’
    • ‘The CIA though has conveniently kept mum as of now.’
    • ‘The fish sign took two people to make - you made a curved line casually on the ground with a toe, if the other person didn't add the other curve you kept mum.’
    • ‘I kept mum about the fact I'd had an abortion.’
    • ‘I presume that the teachers and administration kept mum and can only suppose that it was the boy himself who publicized his problems.’
    • ‘The hospital authorities also kept mum about his visit.’
    • ‘But New York Times staffers kept mum not so much out of fear of reprisals as out of respect for the institution.’
    • ‘Defying the age of celebrity, and resisting the lucrative market for antiquities, the property owner kept mum about his treasure for decades.’
    • ‘Many Gandhians who had kept mum during earlier riots are protesting this time and actively working for restoration of peace.’
    silent, quiet, mute, dumb, tight-lipped, close-mouthed, uncommunicative, unforthcoming, reticent, secretive