estimator
/ˈestɪmeɪtə(r)/noun
1- Statistics a rule, method, or criterion for arriving at an estimate of the value of a parameter【统计】参数值估计（或估算）规则（或方法、标准）。
1.1
- a quantity used or evaluated as such an estimate估计量。
1.2
- a person who estimates the price, value, number, quantity, or extent of something估计者; 评价者。