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.

Any of various membranes or sheets of muscle or ligament which separate one cavity from another.

A contraceptive device consisting of a flexible cup, used to cover the cervix during intercourse.

To reduce lens aperture using an optical diaphragm.

To act as a diaphragm, for example by vibrating.