Dictionary.com
Thesaurus.com

preprocessor

American  
[pree-pros-es-er, -uh-ser, -proh-ses-er, -suh-ser] / ˈpriˌprɒs ɛs ər, -ə sər, -ˌproʊ sɛs ər, -sə sər /

noun

Computers.
  1. 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.


Etymology

Origin of preprocessor

First recorded in 1965–70; pre- + processor