Definitions for ornithineˈɔr nəˌθin
Random House Webster's College Dictionary
an amino acid, H2N(CH2)3CH(NH2)COOH, obtained by the hydrolysis of arginine and occurring as an intermediate compound in the urea cycle of mammals.
Origin of ornithine:
1880–85; ornith(uric acid), secreted by birds + -ine2
an amino acid that does not occur in proteins but is important in the formation of urea
An amino acid, 2,5-diaminopentanoic acid, that is not present in protein, but is an intermediate in the biosynthesis of urea.
U.S. National Library of Medicine
An amino acid produced in the urea cycle by the splitting off of urea from arginine.