Definition of "diaphragm" in Anglais

noun

1. (anatomy) 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.

   • thoracic diaphragm
   • pulmonary diaphragm

2. (anatomy) Any of various membranes or sheets of muscle or ligament which separate one cavity from another.

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

   • cervical diaphragm
   • contraceptive diaphragm

4. (mechanics) 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.

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

   • acoustic diaphragm

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

7. (chemistry) A permeable or semipermeable membrane.

8. (construction) 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.

verb

1. (optics, photography) To reduce lens aperture using an optical diaphragm.

2. To act as a diaphragm, for example by vibrating.