#1 calculus n. [concretion] a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body; "renal calculi can be very painful". wn
#2 calculus n. [tartar, tophus] an incrustation that forms on the teeth and gums. wn
#3 calculus n. [infinitesimal calculus] the branch of mathematics that is concerned with limits and with the differentiation and integration of functions. wn
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