absolute refusal to talk;with one’s mouth sealed ? 王魁為人謹(jǐn)小慎微，平素沉默寡言，有時(shí)甚至～。Wang Kuei was an overcautious person. He was always reticent and sometimes even refused to talk at all.
三緘其口sān jiān qí kǒu
緘：封閉。在其嘴上加了三道封條。比喻說(shuō)話非常小心謹(jǐn)慎，或一句話也不肯說(shuō)。hold one’s peace;with one’s lips sealed, absolute refusal to talk