DIAPHRAGM

diaphragm, stop

(noun) a mechanical device in a camera that controls size of aperture of the lens; “the new cameras adjust the diaphragm automatically”

diaphragm

(noun) electro-acoustic transducer that vibrates to receive or produce sound waves

diaphragm, pessary, contraceptive diaphragm

(noun) 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

diaphragm, midriff

(noun) (anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration

Source: WordNet® 3.1

Etymology

Noun

diaphragm (plural diaphragms)

(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; also called thoracic diaphragm.

(anatomy) 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.

(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.

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

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

(chemistry) A permeable or semipermeable membrane.

(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

diaphragm (third-person singular simple present diaphragms, present participle diaphragming, simple past and past participle diaphragmed)

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

To act as a diaphragm, for example by vibrating.

Source: Wiktionary

Di"a*phragm, n. Etym: [L. diaphragma, Gr. fareire to stuff: cf. F. diaphragme. See Farce.]

1. A dividing membrane or thin partition, commonly with an opening through it.

2. (Anat.)

Definition: The muscular and tendinous partition separating the cavity of the chest from that of the abdomen; the midriff.

3. (Zoöl.)

Definition: A calcareous plate which divides the cavity of certain shells into two parts.

4. (Opt.)

Definition: A plate with an opening, which is generally circular, used in instruments to cut off marginal portions of a beam of light, as at the focus of a telescope.

5. (Mach.)

Definition: A partition in any compartment, for various purposes. Diaphragm pump, one in which a flexible diaphragm takes the place of a piston.

Source: Webster’s Unabridged Dictionary 1913 Edition