diaphragm
/ˈdaɪəfræm; `daɪəˌfræm/ n
1 wall of muscle, between the chest and the abdomen, that helps to control breathing 膈; 膈膜; 横膈膜. =>illus at respire 见respire之插图.
2 arrangement of thin plates in a camera that control how much light is let in through the lens 光圈; 光孔; 光阑.
3 vibrating disc or cone producing sound-waves, eg in telephone receivers, loudspeakers, etc 振动膜（如电话听筒及扬声器等中的）.
4 (also Dutch cap, cap) thin plastic or rubber membrane that is fitted over the neck of the womb before intercourse to prevent conception 子宫帽（避孕用具）.