[ kree-at-n-een, -in ]
/ kriˈæt nˌin, -ɪn /

noun Biochemistry.

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

Nearby words

  1. creatine,
  2. creatine kinase,
  3. creatine phosphate,
  4. creatinemia,
  5. creatininase,
  6. creatinine clearance,
  7. creatinuria,
  8. creation,
  9. creation science,
  10. creationary

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

  • Creatine and creatinine also seem to lessen in amount, but of the extent of this change I am not as yet fully informed.

    Fat and Blood|S. Weir Mitchell
  • The creatinine was estimated in two cases and was found to be 2.0 mg.

    Scurvy Past and Present|Alfred Fabian Hess
  • Foremost among them are uric acid, creatinine, and the coloring-matter.

  • The precipitate contains the picrate of trimethylenediamine, mixed with the picrates of cadaverine and creatinine.

British Dictionary definitions for creatinine


/ (kriːˈætəˌniːn) /


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

Medicine definitions for creatinine


[ 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.

Science definitions for creatinine


[ 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.