English

Verb

keep one's mouth shut

1. (idiomatic) To keep a secret; to refrain from speaking indiscreetly or carelessly; broadly, to refrain from speaking altogether.
   • 1906, Upton Sinclair, The Jungle, Chapter 25

     He thought that he could get him a regular salary if he would come to Packingtown and do as he was told, and keep his mouth shut.

   • 2004, Alan Cowell, "Charles Joins Fray Over Himself," New York Times, 23 Nov. (retrieved 25 Oct. 2008):

     Charles has failed to follow the example of his mother, the queen, who has heroically kept her mouth shut for more than 50 years.

Synonyms

• keep one's lips sealed, keep one's own counsel