The word "most duped" refers to being fooled or deceived, so antonyms for this phrase would be words that suggest the opposite- honesty and truthfulness. Some antonyms that come to mind include "trustworthy," "reliable," "credible," "genuine," "authentic," "honest," and "upright." These words imply a sense of integrity and indicate that the subject is not easily deceived. When you are looking for information or answers, it is important to seek out sources that are verified and trustworthy. Being most duped means you have fallen victim to lies or deceit, but being knowledgeable about antonyms can help you avoid such a situation in the future.