di·​late | \ ˈdī-ˌlāt How to pronounce dilate (audio) , dī-ˈlāt How to pronounce dilate (audio) \
dilated; dilating

Definition of dilate

intransitive verb

1a : to become enlarged or widened Kim's eyes dilated while the outdoor stadium rocked in celebration.— Ralph Wiley … arterioles continually dilate and constrict.— Janet Raloff also : to display or become affected by expansion or widening of a body part The expectant mother was dilating slowly. [=The expectant mother's cervix was dilating slowly.]
b : to become expanded in extent Understandably, a tendency to philosophize dilated with old age.— Anthony Powell Time dilates when you mentally hop continents.— Bret Wallach
2 : to comment at length : discourse usually used with on or upon It's no small irony that a man who made a career out of dilating on failure should have ended up a success.— James AtlasHe dwells and dilates upon every highlight and lowlight …The New Yorker

transitive verb

1a : to enlarge, widen, or cause to expand Nitric oxide is a potent vasodilator that increases blood flow by dilating blood vessels.— Ruth MacPete Inhalers, the standard treatment for asthma, relieve wheezing by delivering an agent that dilates the bronchioles …— Tony Dajer Cocaine … increases the heart rate, raises the blood pressure and, in large doses, increases the body temperature and dilates the pupils of the eyes.— Craif Van Dyke and Robert Byck
b : to expand in extent dilate our cultural knowledge Like millions of other urban youths in the 1960s, Tian got a chance to dilate his horizons when he was sent into the countryside during the Cultural Revolution to learn from the peasantry.— Lawrence Chua
2 archaic : to describe or set forth at length or in detail Do me the favor to dilate at full / What hath befallen of them …— William Shakespeare

Other Words from dilate

dilatability \ (ˌ)dī-​ˌlā-​tə-​ˈbi-​lə-​tē How to pronounce dilate (audio) \ noun
dilatable \ dī-​ˈlā-​tə-​bəl How to pronounce dilate (audio) , ˈdī-​ˌlā-​ How to pronounce dilate (audio) \ adjective
dilator \ dī-​ˈlā-​tər How to pronounce dilate (audio) , ˈdī-​ˌlā-​ \ noun

Choose the Right Synonym for dilate

expand, amplify, swell, distend, inflate, dilate mean to increase in size or volume. expand may apply regardless of the manner of increase (such as growth, unfolding, addition of parts). a business that expands every year amplify implies the extension or enlargement of something inadequate. amplify the statement with details swell implies gradual expansion beyond a thing's original or normal limits. the bureaucracy swelled to unmanageable proportions distend implies outward extension caused by pressure from within. a distended abdomen inflate implies expanding by introduction of air or something insubstantial and suggests a vulnerability to sudden collapse. an inflated ego dilate applies especially to expansion of circumference. dilated pupils

Examples of dilate in a Sentence

The drug causes the blood vessels to dilate. During labor, a woman's cervix will dilate to about 10 centimeters. The drug dilates the blood vessels.
Recent Examples on the Web As your core temperature rises, neurons in your brain’s hypothalamus tell your peripheral blood vessels to dilate; this increases blood flow near the skin, where heat can dissipate through sweat. Dhruv Khullar, The New Yorker, 25 July 2022 To send more blood to the skin’s surface, the heart beats faster and blood vessels dilate to accommodate more blood flow. Dominique Mosbergen, WSJ, 20 July 2022 Try a nasal strip, which uses external tension to dilate the nasal pathways. Scott Lafee, San Diego Union-Tribune, 5 July 2022 Within a few hours, the misoprostol will cause a person’s cervix to dilate and their uterus to contract, emptying the embryo from the person’s uterus. Marina Pitofsky, USA TODAY, 24 June 2022 Immediately prior to the procedure, your doctor will administer eye drops to dilate your pupil and anesthetize your eye. Hoopes Vision, The Salt Lake Tribune, 6 Apr. 2022 According to the American Heart Association, dilated cardiomyopathy causes the heart muscle to dilate and a chamber to enlarge, leading to difficulty when pumping blood and preventing the heart muscle from contracting normally. Wyatte Grantham-philips, USA TODAY, 4 Apr. 2022 In others, muscles surrounding the cloaca could block an unwanted male, or dilate to allow entry to a preferred suitor. Rachel E. Gross, Smithsonian Magazine, 31 Mar. 2022 The hypothesis was that the mild version of non-freezing cold injury might damage the ability of your blood vessels to dilate and bring warm blood to your extremities, and compromise your ability to detect subtle changes in temperature. Alex Hutchinson, Outside Online, 10 Feb. 2021 See More

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

First Known Use of dilate

14th century, in the meaning defined at transitive sense 2

History and Etymology for dilate

Middle English, from Middle French dilater, from Latin dilatare, literally, to spread wide, from dis- + latus wide — more at latitude

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The first known use of dilate was in the 14th century

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Last Updated

4 Aug 2022

Cite this Entry

“Dilate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dilate. Accessed 9 Aug. 2022.

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More Definitions for dilate


di·​late | \ dī-ˈlāt How to pronounce dilate (audio) \
dilated; dilating

Kids Definition of dilate

: to make or grow larger or wider Her pupils dilated in the dark.


di·​late | \ dī-ˈlāt How to pronounce dilate (audio) , ˈdī-ˌ How to pronounce dilate (audio) \
dilated; dilating

Medical Definition of dilate

transitive verb

: to enlarge, widen, or cause to expand dilate his pupils with atropine the drug dilates peripheral arteries

intransitive verb

: to become enlarged, expanded, or widened the cervix was dilating the pupils dilated

More from Merriam-Webster on dilate

Nglish: Translation of dilate for Spanish Speakers

Britannica English: Translation of dilate for Arabic Speakers


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