The antonyms for the word "un-genuine" would be "genuine" or "authentic." When we describe something as genuine, we mean that it is real, honest, and true to its nature. Additionally, a genuine thing or person is free from any deceit or pretense, which may be found in something that is un-genuine. Thus, to negate the word "un-genuine," we can use words that signify the opposite of it. Such antonyms carry a positive connotation and help to describe things that are reliable, trustworthy, and sincere. In summary, using antonyms for "un-genuine" can help us to differentiate between the real and the fake.