(bound form) to seal; to close; to keep silent as in 缄口 jiān​kǒu or 缄默 jiān​mò; to seal a letter (often used on envelopes following the sender's name)

(bound form) a letter or piece of correspondence

(literary) a wooden container or box

(literary) a letter or written correspondence; used interchangeably with 缄 jiān

to close or seal; specifically used for sealing a letter (often following the sender's name on an envelope)