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.
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.
This leads to dehydration and eventually “desertification”—a phenomenon the film tracks across a quasi-equatorial band of the Earth, where deforestation in pursuit of farmland has had a deleterious effect.
From The Wall Street Journal • Jun. 2, 2026
Others are far below, hiking through extreme heat, refilling reservoirs and pouring water over themselves to stay safe from dehydration and heat illness.
From Science Daily • Jun. 2, 2026
Mella said that protecting large, shade-producing trees or providing access to water during heatwaves could help reduce dehydration risk among koalas.
From Barron's • May 26, 2026
My mantra in April is dehydration is serious business.
From Los Angeles Times • Apr. 22, 2026
Derek’s coma was low grade, and in truth he probably would have been all right even if Brian had not made the run—although he would have suffered significantly from dehydration.
From "The River" by Gary Paulsen
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.
