silent
silent as the grave: seegrave.
the silent majority the majority of people, regarded as holding moderate opinions but rarely expressing them.
☞ This phrase was first particularly associated with the US President Richard Nixon, who claimed in his 1968 presidential election campaign to speak for this segment of society.
2012New York Times We've heard from people in the street. We've heard from those who have been hitting away at pots and pans. Now is the time for the silent majority.
the silent treatment a stubborn refusal to talk to someone, especially after a recent argument or disagreement.
2004Julie BurchillSugar Rush If I hadn't been giving her the silent treatment because of my hurt pride, she'd never have even gone off with this psycho.