[kree-at-n-een, -in]

noun Biochemistry.

a crystalline end product of creatine metabolism, C4H7N3O, occurring in urine, muscle, and blood.

Origin of creatinine

1850–55; < German Kreatinin, equivalent to kreatin creatine + -in -ine2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for creatinine

Historical Examples of creatinine

British Dictionary definitions for creatinine



an anhydride of creatine that is abundant in muscle and excreted in the urine

Word Origin for creatinine

C19: from German Kreatinin, from Kreatin creatine + -in -ine ²
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

Word Origin and History for creatinine

by 1847, from creatine + chemical suffix -ine (2).

Online Etymology Dictionary, © 2010 Douglas Harper

creatinine in Medicine


[krē-ătn-ēn′, -ĭn]


A creatine anhydride formed by the metabolism of creatine and found in muscle tissue and blood and normally excreted in the urine as metabolic waste.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

creatinine in Science


[krē-ătn-ēn′, -ĭn]

A compound formed by the metabolism of creatine, found in muscle tissue and blood and normally excreted in the urine as a metabolic waste. Measurement of creatinine levels in the blood is used to evaluate kidney function. Chemical formula: C4H7N3O.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.