late 14c., "mathematician, one who calculates," from L. calculator, from calculatus, pp. of calculare "to reckon, compute," from calculus (see calculus). Of mechanical adding machine contraptions, from 1784. Of electronic ones, from 1946.
"Electronic calculator uses 18,000 tubes to solve complex problems" ["Scientific American" headline, June 1946]
An electronic device for performing automatic mathematical computations, usually controlled by a keyboard. Some are actually small computers, with limited memory, that allow the user to use simple programs.