The term "re double" refers to the act of doubling something again, or repeating it. Its antonyms would include words such as "halve", which means to divide something in half or to reduce it by half. Another antonym could be "reduce", meaning to decrease or diminish something in size, amount, or intensity. "Lessen" would also be an antonym, implying the act of making something smaller or decreasing its significance. Additionally, "shrink" could be an antonym, meaning to reduce in size, amount, or intensity. These antonyms provide an opposing meaning to the term "re double", reflecting the opposite actions of reducing, diminishing, or decreasing something.