Bonafide is an adjective that describes something as genuine, authentic, and legitimate. Its antonyms are words that convey the opposite meaning. The first antonym is counterfeit, implying something that is fake or fraudulent. Another antonym is false, indicating something is not true, real, or genuine. Dishonest is also an antonym as it suggests a lack of integrity or truthfulness. If something is unconfirmed, it has not been verified or authenticated, making it an antonym of bonafide. Finally, words like insincere, fictitious, and fraudulent can all be considered antonyms for bonafide as they indicate a lack of genuineness, authenticity, and legitimacy.