diaphragm

noun

• Muscular membrane separating upper/lower organs
• A dome-shaped, muscular partition separating the thorax from the abdomen in mammals. It plays a major role in breathing, as its contraction increases the volume of the thorax and so inflates the lungs.
• A contraceptive device consisting of a thin rubber or plastic dome that is inserted into the vagina to cover the cervix.
• A thin, usually circular, plate or membrane that vibrates in response to sound waves or light, or that controls the passage of light or fluid.