noun Biochemistry.

an amino acid, NH2CONH(CH2)3CHNH2COOH, abundant in watermelons and an intermediate compound in the urea cycle.

Origin of citrulline

1930; < New Latin citrull(us) the watermelon genus (Medieval Latin citrul(l)us, citrolus, Latinization of South Italian citrulo, Tuscan citri(u)olo < Late Latin citrium watermelon (derivative of Latincitrus (see citrus); apparently in reference to the citroncolored fruit of some types of watermelon), with -uolo < Latin -eolus) + -ine2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for citrulline



an amino acid that occurs in watermelons and is an intermediate in the formation of urea. Formula: NH 2 CONH(CH 2) 3 CHNH 2 COOH

Word Origin for citrulline

C20: from Medieval Latin citrullus a kind of watermelon, from Latin citron, referring to its colour
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

citrulline in Medicine




An amino acid produced as an intermediate in the conversion of ornithine to arginine during urea formation in the liver.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

citrulline in Science



An amino acid originally isolated from watermelon, occurring mostly in the liver as an intermediate in the conversion of ornithine to arginine during urea formation. Chemical formula: C6H13N3O3.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.