/ Thesaurus / I Synonyms of immunizing agent Find synonyms for: Noun1. immunogen, immunizing agent, antigenusage: any substance or organism that provokes an immune response (produces immunity) when introduced into the bodyWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: penury Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language