diaphragm

noun di·a·phragm \ ˈdī-ə-ˌfram \

|Updated on: 4 Aug 2018

Definition of diaphragm

1 : a body partition of muscle and connective tissue; specifically : the partition separating the chest and abdominal cavities in mammals

2 : a dividing membrane or thin partition especially in a tube

3 a : a more or less rigid partition in the body or shell of an invertebrate

b : a transverse septum in a plant stem

4 : a device that limits the aperture of a lens or optical system — compare iris diaphragm

5 : a thin flexible disk (as in a microphone or loudspeaker) that vibrates when struck by sound waves or that vibrates to generate sound waves

6 : a molded cap usually of thin rubber fitted over the uterine cervix to act as a mechanical contraceptive barrier

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diaphragmatic

play \ˌdī-ə-frə(g)-ˈma-tik, -ˌfrag-\ adjective

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diaphragmatically

play \-ˈma-ti-k(ə-)lē\ adverb

See diaphragm defined for English-language learners

See diaphragm defined for kids

Recent Examples of diaphragm from the Web

When the diaphragm goes, so does your ability to inhale; surgical patients administered the drug are typically intubated with a breathing tube, their respiratory status carefully monitored.

— robbie gonzalez, WIRED, "The Untested Drugs at the Heart of Nevada's Execution Controversy," 11 July 2018
Both girls were sharing a liver, sternum and diaphragm.

— sarah schreiber, Good Housekeeping, "Twin Girls Who Were Conjoined at the Stomach Celebrate 2nd Birthday," 27 Oct. 2016
Toyota says a diaphragm material in the fuel injection system can harden over time and crack, allowing fuel to leak.

— BostonGlobe.com, "Boston Children’s named best pediatric hospital in the country for fifth year," 27 June 2018
According to the car manufacturer, the diaphragm material in the fuel pulsation dampers of certain engines can harden over time and crack, allowing fuel to leak and creating a risk of fire.

— renae reints, Fortune, "Lexus Recalls 121,000 Cars Due to Risk of Fuel Leaks," 27 June 2018
In this disorder, a ligament supporting the diaphragm, known as the median arcuate ligament, cuts off circulation not to the colon but to the stomach, by obstructing the artery that delivers blood there.

— lisa sanders, New York Times, "What Was Causing a Healthy Older Man to Be Nauseated by Food?," 13 June 2018
To take advantage of piezoelectricity, Dagdeviren and her colleagues have developed flat devices that can be stuck onto organs and muscles such as the heart, lungs, and diaphragm.

— charles q. choi, The Atlantic, "Your Heartbeat Could Power a Smartphone," 12 Apr. 2018
Women who have endometriosis can have episodes of pneumothorax if those cells make their way past the diaphragm into the chest.

— lisa sanders, m.d., New York Times, "The Woman Was Fit and Healthy. Why Did Her Lung Mysteriously Collapse?," 28 Mar. 2018
Her post-verbal texts are made of glottal stops and hisses, tongue clicks and tones pushed out from the diaphragm.

— peter dobrin, Philly.com, "Daniel Webster, longtime Inquirer classical music critic," 14 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'diaphragm.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of diaphragm

Middle English diafragma, from Late Latin diaphragma, from Greek, from diaphrassein to barricade, from dia- + phrassein to enclose

NEW! Time Traveler

First Known Use: 14th century

in the meaning defined at sense 1

See Words from the same year

Other Anatomy Terms

bilateral symmetry, carotid, cartilage, dorsal, entrails, prehensile, renal, solar plexus, supine, thoracic, ventral

DIAPHRAGM Defined for English Language Learners

diaphragm

noun

Definition of diaphragm for English Language Learners

medical : a large flat muscle that separates the lungs from the stomach area and that is used in breathing
: a device that controls the amount of light passing through the lens of a camera
: a device shaped like a cup that is placed in the vagina to prevent pregnancy

DIAPHRAGM Defined for Kids

diaphragm

noun di·a·phragm \ ˈdī-ə-ˌfram \

Definition of diaphragm for Students

1 : a muscular wall that separates the lungs from the stomach area and assists in breathing in

2 : a thin disk (as in a microphone) that vibrates when sound strikes it

Medical Dictionary

diaphragm

noun di·a·phragm \ ˈdī-ə-ˌfram \

medical Definition of diaphragm

1 : a body partition of muscle and connective tissue; specifically : the partition separating the chest and abdominal cavities in mammals — see pelvic diaphragm, urogenital diaphragm

2 : a device that limits the aperture of a lens or optical system

3 : a molded cap usually of thin rubber fitted over the uterine cervix to act as a mechanical contraceptive barrier