estimator vs actuary

estimator and actuary both are nouns.

Word	Noun	Adjective	Verb	Adverb
estimator	Yes	No	No	No
actuary	Yes	No	No	No

As nouns, actuary is a hyponym of estimator; that is, actuary is a word with a more specific, narrower meaning than estimator:

estimator: an expert at calculation (or at operating calculating machines)
actuary: someone versed in the collection and interpretation of numerical data (especially someone who uses statistics to calculate insurance premiums)

Other hyponyms of estimator include adder, number cruncher, statistician, subtracter.

estimator (noun)	actuary (noun)
an expert at calculation (or at operating calculating machines)	someone versed in the collection and interpretation of numerical data (especially someone who uses statistics to calculate insurance premiums)