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dehydration

American  
[dee-hahy-drey-shuhn] / ˌdi haɪˈdreɪ ʃən /

noun

  • dehydrations
    plural
  1. the act or process of dehydrating.

  2. an abnormal loss of water from the body, especially from illness or physical exertion.


dehydration Scientific  
/ dē′hī-drāshən /
  1. The process of losing or removing water or moisture.

  2. A condition caused by the excessive loss of water from the body, which causes a rise in blood sodium levels. Since dehydration is most often caused by excessive sweating, vomiting, or diarrhea, water loss is usually accompanied by a deficiency of electrolytes. If untreated, severe dehydration can lead to shock.


Other Word Forms

Noun Inflected Forms

Etymology

Origin of dehydration

First recorded in 1850–55; dehydrate + -ion

Explanation

Dehydration is what happens when something has water removed from it. Dehydration makes people extremely thirsty, and it can make plants grow droopy and brown. During dehydration, moisture is lost without being replaced. In humans, dehydration can happen during strenuous exercise or in extreme heat — or simply when someone doesn't drink enough water for a certain length of time. A grape becomes a raisin through dehydration, shriveling and drying as moisture is removed. Dehydration and dehydrate, first used only by scientists, have a Greek root, hydro, "water."

Keep Reading on Vocabulary.com

Vocabulary lists containing dehydration

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:

Bad things happen when we don’t get enough of it, the main one being dehydration, a leading preventable cause of hospitalizations.

From The Wall Street Journal Aug. 27, 2026

People with diarrhea and a high fever, prolonged diarrhea or vomiting, or signs of dehydration should contact their medical provider immediately, the CDC said.

From The Wall Street Journal Aug. 21, 2026

He was taken to hospital in February on the Spanish island of Tenerife while suffering from an infection and dehydration.

From BBC Aug. 17, 2026

The two patients who died may have had underlying health conditions that made them particularly vulnerable to the gastrointestinal illness and dehydration that can come with the disease, Michigan public health officials said.

From Los Angeles Times Aug. 6, 2026

The symptoms of cholera were severe vomiting and diarrhea, leading to dehydration, weakness, and often death.

From "Charles and Emma: The Darwins' Leap of Faith" by Deborah Heiligman

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