柯林斯詞典oxygen mask (oxygen masks) 1. N-COUNT An oxygen mask is a device that is connected to a cylinder of oxygen by means of a tube. It is placed over the nose and mouth of someone who is having difficulty in breathing in order to help them breathe more easily. 氧氣麪罩 返回 oxygen mask劍橋詞典a piece of equipment that can be put over a person's nose and mouth to supply them with oxygen 氧氣麪具,氧氣罩 返回 oxygen mask