What is the meaning of Diaphragm?

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.

A flexible membrane separating two chambers and fixed around its periphery that distends into one or other chamber as the difference in the pressure in the chambers varies.

In a speaker, the thin, semi-rigid membrane which vibrates to produce sound.

A thin opaque structure with a central aperture, used to limit the passage of light into a camera or similar device.

A permeable or semipermeable membrane.

A floor slab, metal wall panel, roof panel or the like, having a sufficiently large in-plane shear stiffness and sufficient strength to transmit horizontal forces to resisting systems.

To reduce lens aperture using an optical diaphragm.

To act as a diaphragm, for example by vibrating.

Source: wiktionary.org