kidney
kid.ney \'kid-ne-\ n [ME] 1a: one of a pair of vertebrate organs situated in the body cavity near the spinal column that excrete waste products of metabolism, in man are bean-shaped organs about 41/2 inches 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 a main cavity whence it is conveyed by the ureter to the bladder 1b: any of various excretory organs of invertebrate animals 2: the kidney of an animal eaten as food by man 3a: TEMPERAMENT, DISPOSITION 3b: KIND, SORT
Webster's English Dictionary