to keep silent; to remain quiet; to be reticent

to seal one's lips; to speak with extreme caution or be very reluctant to speak; to be tight-lipped

to keep one's mouth shut; to remain silent; to hold one's tongue

to keep one's mouth shut and not say a word

a written letter or correspondence

To be extremely careful or cautious in one's speech; refers literally to sealing something with three seals.

honorific term used to refer to another person's letter

(honorific) your letter; a respectful way to refer to correspondence from another person

to keep one's mouth shut as if it were a sealed bottle; to remain silent or keep a secret

The legal right of a defendant in a criminal case to refuse to provide evidence that could be self-incriminating and to remain silent

To be extremely cautious with one's words or to remain silent to avoid trouble; literally "a bronze statue with its mouth sewn shut".