verb di·late \ ˈdī-ˌlāt , dī-ˈ \
|Updated on: 17 Jul 2018

Definition of dilate

dilated; dilating
1 archaic : to describe or set forth at length or in detail
  • dilate at full what hath befallen of them
  • —Shakespeare
2 : to enlarge or expand in bulk or extent : distend, widen
  • dilate our cultural knowledge
  • … long after Italian women used drops of belladonna to artificially dilate their pupils.
  • —Michael H. Robinson
1 : to comment at length : discourse usually used with on or upon
  • dilating upon themes of love and death
2 : to become wide : swell
  • the pupil of the eye dilates and contracts


play \(ˌ)dī-ˌlā-tə-ˈbi-lə-tē\ noun


play \dī-ˈlā-tə-bəl, ˈdī-ˌ\ adjective


play \dī-ˈlā-tər, ˈdī-ˌ\ noun

Examples of dilate in a Sentence

  1. The drug causes the blood vessels to dilate.

  2. During labor, a woman's cervix will dilate to about 10 centimeters.

  3. The drug dilates the blood vessels.

Recent Examples of dilate from the Web

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.

Origin and Etymology of dilate

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

Synonym Discussion of 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

DILATE Defined for English Language Learners


Definition of dilate for English Language Learners

  • : to become larger or wider

DILATE Defined for Kids


verb di·late \ dī-ˈlāt \

Definition of dilate for Students

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

Medical Dictionary


verb di·late \ dī-ˈlāt , ˈdī-ˌ \

medical Definition of dilate

dilated; dilating
: to enlarge, stretch, or cause to expand
  • dilate his pupils with atropine
  • the drug dilates peripheral arteries
: to become expanded or swollen
  • the cervix was dilating
  • the pupils dilated

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to hasten

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