Meanings
nounornithine (countable and uncountable, plural ornithines)
plural ornithines
- countableuncountablebiochemistryAn amino acid, 2,5-diaminopentanoic acid, that is not present in protein, but is an intermediate in the biosynthesis of urea (the urea cycle).
Origin
Blend of ornith- + (ur)ine. The name "ornithine" is in reference to its discovery as a benzoate ester in chicken excrement, by Max Jaffe in 1877.
Full word history & related roots →Translations
Bulgarian орнитин
- орнитин (ornitin)amino acid
Chinese Mandarin 鳥氨酸 /鸟氨酸
- 鳥氨酸 /鸟氨酸 (niǎo'ānsuān)amino acid
French ornithine
- ornithineamino acid
German Ornithin
- Ornithinamino acid
Hungarian ornitin
- ornitinamino acid
Italian ornitina
- ornitinaamino acid
Japanese オルニチン
- オルニチン (orunichin)amino acid
Polish ornityna
- ornitynaamino acid
Romanian ornitină
- ornitinăamino acid
Russian орнитин
- орнитин (ornitin)amino acid
Spanish ornitina
- ornitinaamino acid
Cite this entry
APA
ornithine. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/ornithine
MLA
“ornithine.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/ornithine. Accessed November 3, 2026.
Chicago
WatkinsX Dictionary, s.v. “ornithine,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/ornithine.
Source: ornithine on Wiktionary, CC BY-SA 4.0.