calculus

noun

1.
a hard lump produced by the concretion of mineral salts; found in hollow organs or ducts of the body
concretion
Derived from:
calculous
2.
an incrustation that forms on the teeth and gums
tartar tophus
3.
the branch of mathematics that is concerned with limits and with the differentiation and integration of functions
flowreckoning telgrinding infinitesimal calculus
Derived from:
calculate