Antonyms for the phrase "has a fit" include staying calm, remaining composed, staying level-headed, and keeping one's cool. Instead of lashing out or losing control, one can choose to breathe deeply, take a moment to collect their thoughts, and respond in a more measured and thoughtful way. Other antonyms for "has a fit" could include being patient, showing restraint, exhibiting self-control, and maintaining an even demeanor. It is important to remember that everyone experiences moments of frustration and anger, but it is how we choose to react that can make all the difference in a situation.