[pree-pros-es-er, -uh-ser or, esp. British, -proh-ses-er, -suh-ser]
a program that performs some type of processing, as organization of data or preliminary computation, in advance of another program that will perform most of the processing.
Origin of preprocessor
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019