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 Within a half-hour to a couple of hours, the misoprostol leads the cervix to dilate and the uterus to begin contracting, which empties the embryo from the uterus. Elizabeth Weise, USA TODAY, 7 May 2022 Both erectile dysfunction medications and nitrates cause blood vessels to dilate, which can dramatically escalate if the drugs are taken close together, potentially causing a sharp drop in blood pressure. Benjamin Ryan, NBC News, 18 Apr. 2022 As a result, the levels of cGMP/cAMP increase in the smooth muscle cells that line the walls of your blood vessels, which in turn cause the smooth muscles to relax and the blood vessels to dilate and expand. Bruce Y. Lee, Forbes, 9 Apr. 2022 Blood vessels then dilate to allow fresh nutrients and oxygen to flow to the area and facilitate healing. Dr. Michael Daignault, USA TODAY, 24 Feb. 2022 His hair is white; his eyes dilate behind his rimless glasses. Alexandra Schwartz, The New Yorker, 31 Jan. 2022 Her mouth opens, her pupils dilate, her breathing quickens, and the Wachowskis commit to the bit by zooming in between the woman’s legs and letting her orgasm play out like a cascade of fireworks. Roxana Hadadi, Vulture, 23 Dec. 2021 These foods contain nitrites, which are preservatives known to dilate blood vessels and trigger head pain and migraines, according to the Cleveland Clinic. Sara Lindberg, SELF, 2 Dec. 2021 Your pulse quickens, your pupils dilate, your hairs stand on end. David Fear, Rolling Stone, 24 Nov. 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

12 May 2022

Cite this Entry

“Dilate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dilate. Accessed 23 May. 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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