放风 [- fēnɡ]①(使空气流通) let in fresh air ②(让坐牢的人到院里散步) let prisoners out for exercise or to relieve themselves ③(透露或散布消息) leak certain information; spread news or rumours ④[方] (把风) be on the lookout; act as a lookout 放风阀air pressure release valve; air relief valve