Hotheadedness is a term that describes a tendency to act impulsively or rashly, often without thinking of the consequences. The antonyms for this word are calmness, level-headedness, composure, and equanimity. Calmness refers to a state of tranquility or serenity, while level-headedness suggests an ability to remain rational and clear-headed in challenging situations. Composure is a similar term that connotes a sense of inner calm and poise. Finally, equanimity refers to a mental state that is characterized by a sense of balance and stability, even in the face of adversity. All of these antonyms suggest an ability to remain cool, calm, and collected in difficult situations, which can be a valuable asset in many aspects of life.