In mammals, a sheet of muscle separating the thorax from the abdomen, contracted and relaxed in respiration to draw air into and expel air from the lungs; also called thoracic diaphragm.
User Defined Definitions
"a mechanical device in a camera that controls size of aperture of the lens"
"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"
"electro-acoustic transducer that vibrates to receive or produce sound waves"