dilation
noun
di·la·tion
dī-ˈlā-shən 
plural dilations
: the act or action of enlarging, expanding, or widening : the state of being dilated: such as
a
: the act or process of expanding (such as in extent or volume)
… the dilation of palladium grains undergoing hydrogen absorption.—
Frédéric Favier et al.
Frédéric Favier et al.The thermometer bulbs are subject to thermal and pressure dilation …—Leslie A. Guildner
Leslie A. Guildner
b
: the act or action of stretching, widening, or enlarging an organ or part of the body
dilation of the pupil with atropine
Faced with threatening situations, the body responds with a sudden dilation of blood vessels.—Paul G. Donohue
Paul G. DonohueShe has been treated with esophageal dilation, antacids and cimetidine …—David B. Adams
David B. AdamsThis year in the United States, more than 200,000 balloon dilations of the coronary arteries will be done …—John Stone
John Stone
c
: the condition of being stretched or enlarged beyond normal dimensions : dilatation sense 1a
chronic dilation of arterioles
left ventricular dilation
While the physiological cause of migraines is still unclear, researchers suspect that it involves the prolonged dilation of blood vessels in the brain.—Andrew Weil
Andrew Weil
d
: an increase in duration of an event due to the effects of special relativity (see relativity sense 3a)
However, if the Sun kept its same mass and were made smaller in circumference so its surface was closer to its center, then its gravity would be stronger, and correspondingly its gravitational time dilation—its warpage of time—would become larger.—Kip S. Thorne
Kip S. ThorneA related "time dilation" is caused by gravity: near a large mass, clocks tend to run slow.—Martin Rees
Martin ReesExamples of dilation in a Sentence
Recent Examples on the Web
Quiros suggests bringing sunglasses with you to your appointment since dilation can make your eyes sensitive to light.
—Korin Miller, Verywell Health, 14 Aug. 2024
Dimethyl sulfoxide infused in the vein has also been shown to cause dilation of the blood vessels, hypotension (low blood pressure), and chest pain.
—Kirstyn Hill, Pharmd, Mph, Health, 22 Sep. 2024
So, upon signals of eating, the crossed nerve fibers lead not to salivation but heat responses, including sweat production and blood vessel dilation, which explains the facial flushing.
—Beth Mole, Ars Technica, 10 Sep. 2024
This is accompanied by dilation of the blood vessels leading to the kidney and an increase in the pressure on the filtering units.
—Alex Hutchinson, Outside Online, 10 Sep. 2024
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Korin Miller, Verywell Health, 14 Aug. 2024
Dimethyl sulfoxide infused in the vein has also been shown to cause dilation of the blood vessels, hypotension (low blood pressure), and chest pain.
—Kirstyn Hill, Pharmd, Mph, Health, 22 Sep. 2024
So, upon signals of eating, the crossed nerve fibers lead not to salivation but heat responses, including sweat production and blood vessel dilation, which explains the facial flushing.
—Beth Mole, Ars Technica, 10 Sep. 2024
This is accompanied by dilation of the blood vessels leading to the kidney and an increase in the pressure on the filtering units.
—Alex Hutchinson, Outside Online, 10 Sep. 2024
See all Example Sentences for dilation
Dictionary Entries Near dilation
Cite this Entry
“Dilation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/dilation. Accessed 26 Nov. 2024.
Copy CitationKids Definition
dilation
noun
di·la·tion
dī-ˈlā-shən
1
: the act of dilating : the state of being dilated : expansion
dilation of the pupils of the eyes
2
: the action of stretching or enlarging an organ or part of the body
Medical Definition
dilation
noun
di·la·tion
dī-ˈlā-shən
1
a
: the state of being dilated
monitored cervical dilation
b
: the act or action of stretching, widening, or enlarging an organ or part of the body
dilation of the pupil with atropine
2
: the condition of being stretched or enlarged beyond normal dimensions : dilatation sense 1a
chronic dilation of the arterioles
left ventricular dilation
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