The word "boisterousnesses" refers to a state of being noisy, rowdy, and energetic. Antonyms for this word would be words that describe calmness, tranquility, and peace. Some words that could be used as antonyms for "boisterousnesses" include serenity, calmness, quietness, quietude, peacefulness, and stillness. These words convey a sense of calmness and composure, which are the opposite of the high-energy and noisy state associated with "boisterousnesses". By using these antonyms, a writer can convey a sense of relaxation and peace, which can be an effective way to contrast with scenes or situations that are characterized by noise and activity.