The phrase "double dealt" often refers to deception or betrayal, so antonyms for this phrase could include words that reflect honesty and loyalty. Some possibilities might include "sincere," "trustworthy," "straightforward," "forthright," or "transparent." These words convey a sense of integrity and reliability, and suggest that the person in question is someone who can be trusted and relied on. Other possible antonyms for "double dealt" might include words that reflect openness and fairness, such as "fair-minded," "impartial," or "equitable." Ultimately, the choice of antonyms will depend on the context and intended meaning of the phrase.