calculi

plural of calculus

(countable, dated) Calculation; computation.
(countable) Any formal system in which symbolic expressions are manipulated according to fixed rules.
(definite, often, uncountable) Differential calculus and integral calculus considered as a single subject.
(countable) A stony concretion that forms in a bodily organ.
(uncountable) Deposits of calcium phosphate salts on teeth.
(countable) A decision-making method, especially one appropriate for a specialised realm.