Noun
lambda calculus (countable and uncountable, plural lambda calculi)
(computing theory) Any of a family of functionally complete algebraic systems in which lambda expressions are evaluated according to a fixed set of rules to produce values, which may themselves be lambda expressions.
Lambda calculus may be typed and untyped. Source: Internet
History Lambda calculus provides a theoretical framework for describing functions and their evaluation. Source: Internet
Lambda calculus reifies "functions" and makes them first-class objects, which raises implementation complexity when it is implemented. Source: Internet