diaphragm


diaphragm (http://definr.com/diaphragm)

     n 1: a mechanical device in a camera that controls size of
          aperture of the lens; "the new cameras adjust the
          diaphragm automatically" [syn: stop]
     2: (anatomy) a muscular partition separating the abdominal and
        thoracic cavities; functions in respiration [syn: midriff]
     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 [syn: pessary,
         contraceptive diaphragm]
     4: electro-acoustic transducer that vibrates to receive or
        produce sound waves