ㄐㄧㄢjiānㄎㄡˇkǒuㄅㄨˋㄧㄢˊyán

  1. 說話·八九·》:正德御史挾勢凌人便朝廷闕失大奸緘口不言。」緘舌閉口守口如瓶

lips sealed and not saying anything (idiom)​; fig. to omit mention (of a non-person or embarrassing topic)​, to censor