The antonyms for the word "excitabilities" are calmness, serenity, composure, tranquility, and equanimity. These words represent the opposite of being excitable; they indicate a state of peacefulness and stillness. While excitability implies a tendency to become easily agitated or stimulated, these antonyms suggest a sense of tranquility and self-possession. By using these antonyms, we can communicate the opposite of excitabilities and express a state of peace and calmness. Being able to identify and use antonyms effectively can help us communicate more clearly, and convey our message with greater accuracy and precision.