The term "casts aspersion" means to criticize or speak ill of someone or something. The antonyms for this phrase would be to praise, compliment, or admire. Instead of casting aspersions, one can give credit, express reverence, or commend the subject. Antonyms serve to convey the opposite meaning of a word, and in this case, they offer a positive alternative to a negative expression. It is essential to use antonyms carefully because they can change the whole context and tone of the sentence. Therefore, always consider the context before using an antonym to ensure that it has the right effect.