/ Thesaurus / I Synonyms of illegalise Find synonyms for: Verb1. outlaw, criminalize, criminalise, illegalize, illegalise, forbid, prohibit, interdict, proscribe, veto, disallow, nixusage: declare illegal; outlaw; "Marijuana is criminalized in the U.S."WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language