"Illegalizes" refers to making something illegal or banning it by law. Some antonyms for this word could be "legalizes," which means to make something legal and acceptable, or "authorizes," which implies giving official permission or approval to something. Other antonyms for "illegalizes" could include "approves," "permits," or "enables," all of which convey the sense of making something allowable, legitimate, or acceptable. Ultimately, antonyms for "illegalizes" are words that describe actions that are sanctioned, legitimate, and lawful, which are opposite in meaning to making something illegal or prohibited.