calculus

noun

1. (countable, dated)Calculation; computation.
2. (countable)Any formal system in which symbolic expressions are manipulated according to fixed rules.

   “lambda calculus”

   “predicate calculus”

3. (definite, often, uncountable)Differential calculus and integral calculus considered as a single subject.

   “Near-synonyms: analysis, mathematical analysis”

   “I took calculus in high school.”

4. (countable)A stony concretion that forms in a bodily organ.

   “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.”

5. (uncountable)Deposits of calcium phosphate salts on teeth.
6. (countable)A decision-making method, especially one appropriate for a specialised realm.

   “The Tory leader refused to state how many financiers he thought should end up in jail, saying: “There is not some simple calculus."”