n.
A semisolid compound, C5H4N4O3, that is a nitrogenous end product of protein and purine metabolism and is the chief nitrogenous component of the urine in birds, terrestrial reptiles, and insects.
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.