silencer
n
(a) (Brit) (US muffler) device that reduces the noise made by a vehicle's exhaust (機動車的)消聲器. =>illus at App 1 見附錄1插圖, page xii.
(b) device that reduces the noise made by a gun being fired (槍的)消聲器. silence interj be quiet 安靜; 別出聲
`Silence!' shouted the teacher. `安靜!'教師喊道.