Definition of "calculus"

calculus

/ˈkæl.kjʊ.ləs/

noun
countable and uncountable, plural calculi or calculuses
1. (dated, countable) Calculation; computation.
2. (countable, mathematics) Any formal system in which symbolic expressions are manipulated according to fixed rules.
3. (uncountable, often definite, the calculus) Differential calculus and integral calculus considered as a single subject; analysis.
4. (countable, medicine) A stony concretion that forms in a bodily organ.
  Quotations
  Commonly indicated for treatment of sour crop (Fig. 11-11, A), an ingluviotomy is done to retrieve crop calculi, ingluvioliths, or foreign bodies (which are not accessible per os) or to retrieve proventricular or ventricular foreign bodies (using micromagnets [glued in place within plastic tubes], lavage, or endoscopy) and for the placement of an ingluviotomy or proventriculotomy tube or the collection of crop wall biopsies.
  2015, Jaime Samour, Avian Medicine, page 297
5. (uncountable, dentistry) Deposits of calcium phosphate salts on teeth.
6. (countable) A decision-making method, especially one appropriate for a specialised realm.
  Quotations
  The Tory leader refused to state how many financiers he thought should end up in jail, saying: “There is not some simple calculus."
  2008 December 16, “Cameron calls for bankers’ ‘day of reckoning’”, in Financial Times