The antonyms for the phrase "Say again" are simple and straightforward. One opposite for "Say again" is "Don't repeat," meaning that no further clarification or repetition is necessary. Another antonym is "Remain silent," indicating that no words need to be spoken in response. The third antonym is "Understand completely," implying that the message has been received and deciphered accurately on the first attempt. Each of these antonyms represents a clear, contrasting concept that highlights the different ways in which communication can be interpreted and articulated. By understanding these alternatives, we can achieve more effective and precise interactions with others.