Definition of "kidney" []

• Anatomy Either one of a pair of organs in the dorsal region of the vertebrate abdominal cavity, functioning to maintain proper water and electrolyte balance, regulate acid-base concentration, and filter the blood of metabolic wastes, which are then excreted as urine. (noun)
• The kidney of certain animals, eaten as food. (noun)
• An excretory organ of certain invertebrates. (noun)
• Temperment; kind: a person of the same kidney. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It takes place normally, to a slight extent, in certain cultivated forms of cotton, wherein the seeds are aggregated together into a reniform mass, whence the term kidney cotton."
• "The membrane to the front of the kidney is the lung."
• "Also, as you know, paying a donor for a kidney is a no-no."