the anhydride of creatine, CHNO, found in blood, muscle, and esp. urine, where measurement of its excretion is used to evaluate kidney function
Origin:
Ger kreatinin < kreatin (see creatine) + -ine
See creatinine in American Heritage Dictionary 4
noun
A creatine anhydride, C4H7N3O, formed by the metabolism of creatine, that is found in muscle tissue and blood and normally excreted in the urine as a metabolic waste.