kidneys

kid·ney   (kĭd'nē)    n.   pl. kid·neys 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. The kidney of certain animals, eaten as food. An excretory organ of certain invertebrates. Temperment; kind: a person of the same kidney. [Middle English kidenei.]

kidneys

A pair of organs, the principal parts of the excretory system, located above the waistline at the back of the abdominal cavity. The kidneys filter waste materials from the blood, excreting these wastes in the form of urine; they also regulate the amounts of water and other chemicals in body fluids.

kidney 

Main Entry: kid·ney
Pronunciation: 'kid-nE
Function: noun
Inflected Form: plural kidneys
1 : one of a pair of vertebrateorgans situated in the body cavity near the spinal column that excrete waste products of metabolism, in humans are bean-shaped organs about 4¹/₂ inches(11¹/₂ centimeters) long lying behind the peritoneum in a mass of fatty tissue, and consist chiefly of nephrons by which urine is secreted, collected, and discharged into thepelvis of the kidney whence it is conveyed by the ureter to the bladder —compare MESONEPHROS, METANEPHROS, PRONEPHROS
2 : any of various excretory organs of invertebrate animals

kidney kid·ney (kĭd'nē)
n. pl. kid·neys
Either 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.