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

noun Computers.

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

First recorded in 1965–70; pre- + processor Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020