A reduction strATegy which delays evaluATion of function arguments until they are needed because they are arguments to a primitive function or a conditional. Call-by-need is one part of lazy evaluATion. The term first appears in Chris Wadsworth' s thesis "Semantics and PragmATics of the Lambda calculus" (Oxford, 1971, p. 183). It was used lATer, by J. Vuillemin in his thesis (Stanford, 1973). (1995-05-27)