The antonyms for the word "more hysteric" would be "calm", "composed", "cool", "collected", "serene", "tranquil", "placid", and "level-headed". Someone who is described as "more hysteric" is usually easily agitated, panicked, or nervous. In contrast, someone who is calm and level-headed tends to be collected and in control of their emotions, even in stressful situations. People with tranquil and placid personalities are peaceful and untroubled, without anxiety or disturbance. Being composed means that someone is maintaining self-control and staying centered, rather than becoming erratic or unpredictable, which is the opposite of being hysteric.