The word "most strepitous" means extremely loud or noisy. Its antonyms can be words like silent, quiet, peaceful, calm, hushed, tranquil, serene, subdued, muffled, or faint. These words describe the opposite of the loud and boisterous noise that "most strepitous" implies. The use of antonyms is important in language and communication to provide contrast and balance to statements. By understanding the antonyms of a word, we can better understand its meaning and use it effectively in writing and speaking. Therefore, it is essential to have a good knowledge of antonyms to enhance our vocabulary and communication skills.