The Collaborative International Dictionary
Renal calculus
Renal calculus \Renal calculus\ (Med.), an abnormal concretion formed in the excretory passages of the kidney, composed primarily of calcium oxalates and phosphates; -- also called kidney stone, nephrolith, and nephritic calculus (an obsolete term).
WordNet
renal calculus
n. a calculus formed in the kidney [syn: kidney stone, urinary calculus, nephrolith]