from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of the numerous filtering units of the vertebrate kidney that remove waste matter from the blood.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The basic structural and functional unit of the kidney, which filters the blood in order to regulate chemical concentrations, and thereby produces urine.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of the small tubules that are the excretory units of the vertebrate kidney
German, from Greek nephros, kidney.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Ancient Greek νεφρός (nephros, "kidney"). (Wiktionary)