The antonyms for the word "most rackety" could be words such as quiet, peaceful, tranquil, calm, serene, or still. These words represent a sense of calmness and quietness, which is the opposite of something that is characterized as being "rackety". Rackety can be used to describe something or someone that is loud, chaotic, and noisy. Thus, by using antonyms such as calm or peaceful, we can describe a place, situation, or person that is the opposite of something that is most rackety. These words can be used to create a sense of balance or harmony in our language and communication.