The word "more deceivable" implies that something is highly susceptible to being deceived. Therefore, antonyms for this word would suggest a high level of credibility or trustworthiness. Words like "reliable", "truthful", "honest", "valid", and "authentic" are some of the antonyms for "more deceivable". These words indicate that something or someone is dependable and can be relied upon to provide accurate information or perform as promised, without any hidden agendas or deceptions. Using these antonyms in place of "more deceivable" would convey a completely opposite meaning, suggesting a sense of trust, honesty and transparency.