ˈȯ(r)nəˌthēn noun
( -s )
Etymology: International Scientific Vocabulary ornith- (in ornithuric acid ) + -ine
: a crystalline or syrupy basic amino acid H 2 N(CH 2 ) 3 CH(NH 2 )COOH formed together with urea by hydrolysis of arginine (as by arginase) and in turn converted by reaction with ammonia and carbon dioxide into citrulline and then arginine; α,δ-diamino-valeric acid