kidney
Americannoun
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kidneys
plural
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Anatomy. either of a pair of bean-shaped organs in the back part of the abdominal cavity that form and excrete urine, regulate fluid and electrolyte balance, and act as endocrine glands.
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Zoology. a corresponding organ in other vertebrate animals or an organ of like function in invertebrates.
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the meat of an animal's kidney used as food.
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constitution or temperament.
He was a quiet child, of a different kidney from his boisterous brothers.
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kind, sort, or class.
He is only at ease with men of his own kidney.
noun
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either of two bean-shaped organs at the back of the abdominal cavity in man, one on each side of the spinal column. They maintain water and electrolyte balance and filter waste products from the blood, which are excreted as urine
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the corresponding organ in other animals
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the kidneys of certain animals used as food
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class, type, or disposition (esp in the phrases of the same or a different kidney )
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Either of a pair of organs that are located in the rear of the abdominal cavity in vertebrates. The kidneys regulate fluid balance in the body and filter out wastes from the blood in the form of urine. The functional unit of the kidney is the nephron. Wastes filtered from the blood by the nephrons drain into the ureters, muscular tubes that connect each kidney to the bladder.
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See also nephron
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Etymology
Origin of kidney
1275–1325; Middle English kidenei, kidenere (singular), kideneres, kideneren (plural); origin uncertain; perhaps a compound based either on nere (singular), neres (plural) kidney ( Old English *nēore; compare Old High German nioro, Old Norse nȳra ); or ei (singular), eiren (plural) egg 1, Old English ǣg (singular), ǣgru (plural) (by association with the organ's shape); for the first element compare dial. kid pod (akin to cod 2 )
Explanation
Most people are born with two kidneys, internal organs with the job of filtering waste and excreting urine. All vertebrates — animals with spines — have kidneys. Human kidneys are shaped like large beans, and this is where the "kidney bean," a common red-colored bean, gets its name. The organs called kidneys are vital to life, as they filter bad stuff from your blood, help your body get rid of waste, regulate your blood pressure, and even produce hormones. The word kidney is probably a compound of the Old English cwið, "womb," and ey, "egg," describing the organ's shape.
Vocabulary lists containing kidney
Human Anatomy and Physiology - Introductory
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Human Anatomy and Physiology - High School
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Human Anatomy and Physiology - Middle School
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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:
Side effects can include nausea, vomiting, constipation, diarrhoea and, more rarely, gallbladder or kidney problems and depression.
From BBC ● Aug. 17, 2026
Experts later determined she suffered from severe anemia; blood clots in both wings and one kidney; liver and lung abnormalities; and inadequate bone marrow response.
From Los Angeles Times ● Aug. 14, 2026
Researchers tested ruptoblasts against E. coli bacteria, human kidney cells, and mouse blood cells.
From Science Daily ● Aug. 5, 2026
Bhasin says certain at-risk subsets of the population should be screened, such as people with chronic kidney disease on dialysis, men who have been treated with chemotherapy, or have chronic liver disease.
From The Wall Street Journal ● Jul. 31, 2026
I saw a number of labels for familiar organs—liver, kidney, intestines—but there was nothing human-like about the way the shark’s organs were arranged.
From "The Line Tender" by Kate Allen
According to the outlet, Collins has permanent scarring on his pancreas, and his kidneys “barely” function.
From Los Angeles Times ● Aug. 3, 2026
Lungs, heart, kidneys, liver, brain, testicles, the fluid in our eyes, and ovaries—all have microplastics, says Stapleton.
From The Wall Street Journal ● Jul. 17, 2026
This rare condition, which mostly impacts children, occurs when bacterial toxins spread throughout the body and damage red blood cells, causing clots in the organs, primarily the kidneys.
From Salon ● Jun. 22, 2026
Little did she know she was putting her kidneys under immense strain.
From BBC ● Jun. 20, 2026
“Think about how your kidneys are gonna blow up soon, if you don’t take a whizz pretty soon,” Ben said.
From "The Great Santini" by Pat Conroy
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.
