The word "immunifacient" (ɪˌmjuːnɪˈfeɪʃənt) refers to a substance or agent that enhances or stimulates the immune system. The spelling of this word can be broken down into its Latin roots: "immuni" meaning immune, and "facient" meaning making or causing. By combining these roots, we get "immunifacient," which accurately describes something that supports or aides the immune system. Phonetic transcription can help clarify the pronunciation of unfamiliar words and aid in their proper usage.
Making immune, said of a semelincident disease or of a prophylactic serum or vaccine.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.