The antonyms for the word "un-peaceful" include "calm," "peaceful," "serene," "tranquil," and "harmonious." These words represent a state of peacefulness and relaxation, where there is no disturbance or conflict. Other antonyms for "un-peaceful" can include "orderly," "peaceable," "amicable," and "conciliatory." These words are used to describe situations or relationships that are free from tension, hostility, or aggression. In essence, these antonyms embody the ideal state of being where there is no unrest, turmoil, or conflict. By using these words in our daily conversations, we can promote the values of peace, harmony, and tranquility in our society.