dilation
AmericanOther Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of dilation
Explanation
Dilation is expansion, usually of an opening such as the pupil. When that happens, your eyes look black and the light comes streaming in. Grab your sunglasses! The word dilation is the noun form of dilate, "to make wider.” Dilation often refers to what happens when a woman goes into labor, and her cervix dilates to let the baby through. Dilation is also used for writing or speech that expands on a topic. Here’s a dilation: funny thing is that the -ate ending of dilate is not a suffix but part of the word, so it should really be dilatation, but no one says it that way.
Vocabulary lists containing dilation
The Woman Warrior
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
STAAR Grade 8 Mathematics: Geometry and Measurement, List 1
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Caffeine temporarily shrinks blood vessels and less dilation means less visible swelling.
From BBC ● Feb. 16, 2026
Not only do we tend to mirror each other’s movements, postures, facial expressions and gestures; we also uncannily sync up our heart rates, blood pressure, pupil dilation and hormonal activity.
From The Wall Street Journal ● Jan. 22, 2026
Time itself passes differently at such distances -- a phenomenon known as cosmological time dilation.
From Science Daily ● Nov. 7, 2025
She developed a serious infection and went to the hospital, where physicians would ordinarily have performed a dilation and curettage to remove the remaining tissue.
From Slate ● Sep. 19, 2024
“But not to the physical stimulus; you’re not measuring dilation, for instance. It’ll be to the verbal questions; what we call a flinch reaction.”
From "Do Androids Dream of Electric Sheep?" by Philip K. Dick
However, when it comes to problems with angina, the study shows that it is possible to avoid patients coming back for new balloon dilations through preventive treatment.
From Science Daily ● Apr. 8, 2024
Like all beauties, these are dilations of time.
From New York Times ● Mar. 9, 2021
The stopped time of a painting, say, or the dilations of the novel, in which it is possible to see patterns and consequences that are otherwise invisible.
From The Guardian ● Mar. 21, 2020
The results showed that people with consistently larger pupil dilations made the most erratic decisions.
From Forbes ● Sep. 24, 2014
All the temporal dilations we had gone through were catching up with me.
From "Darius the Great Is Not Okay" by Adib Khorram
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
