"Phonied up" is a slang term that means that something is contrived, false, or pretend. Antonyms for this word include genuine, sincere, authentic, real, and honest. When something is genuine, it is free from deception or fraud, and is an accurate representation of the truth. Sincere denotes a deep and honest feeling that comes from the heart. Authentic means something is true to its origins and has not been altered in any way. Real is something that exists objectively and is not imagined or contrived. Honest means being truthful and transparent about one's actions or intentions. By using an antonym of "phonied up," we can convey a message of trust, authenticity, and truthfulness.