"Wert of the opinion" refers to being convinced or having a particular belief about something. The antonyms for this phrase could be "undecided," "uncertain," "doubtful," "unsure," "wavering," "vacillating," or "indecisive." These words suggest a lack of confidence in one's own belief, and a need for further information or persuasion before making a decision. To say someone is not "of the opinion" could also mean they disagree with the idea entirely, in which case antonyms could be "opposed," "contrary," "antithetical," "diametrically opposed," or "at odds." These words suggest a fundamental difference in perspective or values.