Dictionary.com
definitions

number-cruncher

or num·ber crunch·er

[nuhm-ber-kruhn-cher]
noun Informal.
  1. a person or thing that performs a great many numerical calculations, as a financial analyst, statistician, computer, or computer program.

Origin of number-cruncher

First recorded in 1965–70
Related formsnum·ber-crunch·ing, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for number crunching

number crunching

noun
  1. computing the large-scale processing of numerical data
Derived Formsnumber cruncher, noun
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012