: 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.
The thermometer bulbs are subject to thermal and pressure dilation … 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
She has been treated with esophageal dilation, antacids and cimetidine … David B. Adams
This year in the United States, more than 200,000 balloon dilations of the coronary arteries will be done … John Stone
c
: the condition of being stretched or enlarged beyond normal dimensions : dilatationsense 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
d
: an increase in duration of an event due to the effects of special relativity (see relativitysense 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
A related "time dilation" is caused by gravity: near a large mass, clocks tend to run slow. Martin Rees
Example Sentences
Recent Examples on the WebSymptoms include trembling, salivation, lack of coordination, dilation of the pupils, rapid and weak pulse, respiratory paralysis and gastrointestinal irritation. Camille Fine, USA TODAY, 30 June 2021 The New York Times reported last month that a 35-year-old woman in the Dallas-Fort Worth area was denied a dilation and evacuation procedure for her first-trimester miscarriage, despite severe pain and bleeding. Harris Meyer, Scientific American, 9 Aug. 2022 In Nebraska, Methodist Health System in Omaha has just two specialists with expertise in high-risk pregnancies who also can perform dilation and evacuation procedures to remove a fetus. Christopher Rowland, Washington Post, 6 Aug. 2022 In Nebraska, Methodist Health System in Omaha has just two specialists with expertise in high-risk pregnancies who also can perform dilation and evacuation procedures to remove a fetus. Christopher Rowland, BostonGlobe.com, 6 Aug. 2022 The ruling stemmed from a 2015 case challenging a Kansas law that aimed to largely ban dilation and evacuation, a method used in most second-trimester abortions. Meredith Deliso, ABC News, 27 July 2022 Dilation and curettage procedures involve the dilation of the cervix and removal of contents from the uterus using either suction or scraping of tissue. Sarah Swetlik | Sswetlik@al.com, al, 6 July 2022 First, she would be given medication to induce dilation, and sent to her hotel room to wait.New York Times, 1 Aug. 2022 The woman’s doctor suggested ending the pregnancy via a dilation and evacuation rather than subjecting her patient to the anguish of a pointless labor, according to an affidavit the doctor filed in court, as reported by the Advocate. Monica Hesse, Washington Post, 22 July 2022 See More