dehydration
Americannoun
-
the act or process of dehydrating.
-
an abnormal loss of water from the body, especially from illness or physical exertion.
-
The process of losing or removing water or moisture.
-
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
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."
Vocabulary lists containing dehydration
Elements of the Universe: Hydr, Hydro ("Water")
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!
Dry
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!
hydr, hydro
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
The illness generally isn’t deadly, but diarrhea—which if untreated may last a month—can cause dangerous dehydration.
From Slate ● Jul. 17, 2026
If left untreated, a cyclosporiasis infection can lead to dehydration quickly in the warm summer months, particularly among the elderly, young children and those with a compromised immune system.
From Los Angeles Times ● Jul. 14, 2026
Increased use of GLP-1 weight-loss drugs, which can raise the risk of dehydration, is also a factor.
From MarketWatch ● Jul. 11, 2026
After dozens of rounds of diarrhea, she went to the local emergency room, where she said she was diagnosed with cyclosporiasis and treated for severe dehydration.
From The Wall Street Journal ● Jul. 10, 2026
Luna at the infirmary must have talked about dehydration.
From "The House of the Scorpion" by Nancy Farmer
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.
