The Collaborative International Dictionary of English v.0.48:
Estimator \Es"ti*ma`tor\, n. [L. aestimator.] One who estimates or values; a valuer. --Jer. Taylor. Estivate EstivalWordNet (r) 3.0 (2006):
estimator n 1: an expert at calculation (or at operating calculating machines) [syn: calculator, reckoner, figurer, estimator, computer]