diaphragm

Meanings

Plural: diaphragms

Noun

• a mechanical device in a camera that controls size of aperture of the lens
  • "the new cameras adjust the diaphragm automatically"
• (anatomy) a muscular partition separating the abdominal and thoracic cavities; functions in respiration
• 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
• electro-acoustic transducer that vibrates to receive or produce sound waves
• 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.

Verb

• To reduce lens aperture using an optical diaphragm.
• To act as a diaphragm, for example by vibrating.

Synonyms

contraceptive diaphragm, midriff, pessary, stop