1.a mechanical device in a camera that controls size of aperture of the lens;
the new cameras adjust the diaphragm automatically
2.(anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration
3.a contraceptive device consisting of a flexible dome-shaped cup made of rubber or plastic; it is filled with spermicide and fitted over the uterine cervix
4.electro-acoustic transducer that vibrates to receive or produce sound waves