estimator Syllabification: (es·ti·ma·tor)Pronunciation: /ˈestəˌmātər/Translate estimator | into French | into Italian Definition of estimator noun 1 Statistics a rule, method, or criterion for arriving at an estimate of the value of a parameter. a quantity used or evaluated as an estimate. 2a person who estimates the price, value, number, quantity, or extent of something. estimator in other Oxford dictionaries Definition of estimator in the British & World English dictionary