noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   An amino acid, 2,5-diaminopentanoic acid, that is not present in protein, but is an intermediate in the biosynthesis of urea. countable, uncountable
2. 2
   an amino acid that does not occur in proteins but is important in the formation of urea wordnet

Etymology

Blend of ornith- + (ur)ine.

Related phrases

ornithine carbamoyltransferaseornithine cycleornithine transcarbamylaseornithine transcarbamylase deficiencyamino acid

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.