The word "un-frank" is an adjective that describes a lack of honesty, openness, or candidness. Antonyms for this word might include "frank," "honest," "open," "candid," "truthful," "forthright," "sincere," and "direct." These words all describe qualities of communication that are characterized by transparency, sincerity, and a willingness to share information openly and honestly. The antonyms of "un-frank" describe communication styles that are both empathetic and effective, as they prioritize the importance of truthful and transparent dialogue. In relationships, business, and personal interactions, being frank and honest is always the better policy.