• synonyms


[ uh-lan-toh-in ]
/ əˈlæn toʊ ɪn /

noun Biochemistry, Pharmacology.

a white powder, C4H6N4O3, produced by oxidation of uric acid and the major excretory product of purine degradation in many vertebrates: used medicinally to heal skin ulcers and in lotions, lipsticks, etc., for its soothing effect.

Nearby words

allantoic stalk, allantoic vesicle, allantoid, allantoid membrane, allantoidoangiopagous twins, allantoin, allantoinuria, allantois, allargando, allative, allay

Origin of allantoin

1835–45; allanto(is) + -in2; so named because it is found in the fluid of the allantois Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for allantoin


/ (ˌælənˈtəʊɪn) /


a substance derived from the secretions of snails and contained in some plants, used in skin care products and valued for its soothing properties

Word Origin for allantoin

C19: from allantois
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

Medicine definitions for allantoin


[ ə-lăntō-ĭn ]


A substance present in allantoic fluid, amniotic fluid, and fetal urine.
A crystalline oxidation product of uric acid produced in vertebrate purine metabolism and used medicinally to promote tissue growth.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.