Meaning of ESTIMATION in English

In mathematics, use of a function or formula to derive a solution or make a prediction.

Unlike approximation, it has precise connotations. In statistics, for example, it connotes the careful selection and testing of a function called an estimator. In calculus, it usually refers to an initial guess for a solution to an equation, which is gradually refined by a process that generates closer estimates. The difference between the estimate and the exact value is the error .

Britannica English dictionary.      Английский словарь Британика.