The phrase "hath a fit" typically refers to a sudden outburst of anger or frustration. Antonyms for this phrase might include terms like "calm," "composed," "collected," "unperturbed," or "cool-headed." These words describe an individual who is in control of their emotions and can maintain a sense of peace even in difficult situations. Other potential antonyms might include "restrained," "mild-mannered," "patient," or "easy-going," which indicate a lack of explosive or unpredictable behavior. Whatever the context, these antonyms provide a useful contrast to the idea of "hath a fit," suggesting alternative ways of responding to stress or conflict.