From Longman Dictionary of Contemporary Englishhold your tonguehold your tongue spoken used to tell someone to stop talking or to not tell someone about something I reckon you’ve just got to learn to hold your tongue. → hold
Examples from the Corpus
hold your tongue• If he was a count he would be doubly arrogant and she would not be able to hold her tongue.• She tried to talk him into letting her go, but he ordered her sharply to hold her tongue.• Out of sheer curiosity I held my tongue, and waited.• Learn to hold your tongue, Mistress Philippa, else grief will come of it.• You have to avoid being Nellie-know-all and hold your tongue to allow a younger generation to enjoy the fun of discovery.• Chastised, Elder Brother held his tongue, turning to look at Jinju as if to seek her support.• Jim was struggling to hold his tongue when Carole knocked on his door and walked in.• Stella was forced to hold her tongue when Dotty or Babs Osborne spoke slightingly of Meredith. 