The word "more rumbling" refers to a sound that is deep and continuous, often resembling the sound of thunder or an earthquake. Antonyms, on the other hand, are words that have the opposite meaning to a given word. Antonyms for "more rumbling" would therefore refer to sounds that are soft, gentle, and quiet. Such examples may include the words like whispered, hushed, muffled, subdued, or muted. Rather than being loud and jarring, antonyms for "more rumbling" create a sense of peace and tranquility. By using these antonyms, writers can express a range of emotions, from the calm and serene to the dramatic and intense.