Hystericism is a term that refers to a state of extreme emotional disturbance, often characterized by uncontrollable weeping, laughter, or other forms of exaggerated behavior. Some antonyms for this term might include calmness, composure, serenity, or equanimity. These words suggest a sense of inner peace and tranquility, as opposed to the chaotic and frantic nature of hystericism. Other antonyms might include rationality, sobriety, or level-headedness, which connote an ability to think clearly and make rational decisions, even in the face of difficult emotions or challenging situations. Overall, the antonyms for hystericism all suggest a sense of emotional stability and balance, in contrast to the extreme emotional expressions associated with hystericism.