There are many ways to express the sentiment of "kept your shirt on." It can be defined as remaining calm, patient, and composed in a stressful situation. Some synonyms to describe this behavior include staying levelheaded, maintaining composure, keeping one's cool, showing restraint, exercising self-control, and being stoic. Each of these terms emphasizes the importance of maintaining a controlled demeanor, even in the face of adversity or frustration. Ultimately, keeping your shirt on means possessing the ability to maintain an even keel in any situation, no matter how challenging it may be. This kind of calm demeanor can be a valuable asset in both personal and professional settings.