The word "controversialize" refers to the act of making something controversial or causing a disagreement or argument over a particular topic or issue. To express the opposite meaning of controversialize, some antonyms that can be used are "unify," "agree," "harmonize," "conform," "cooperate," "concur," "support," "settle," "resolve," "validate," "endorse," and "sanction." These words signify a sense of agreement, cooperation and unity instead of discord and dissent. By adopting these antonyms, one can convey a more harmonious and conciliatory tone in their language and ideas, fostering better understanding and agreement on that particular issue or topic.