Blow one's tops is an idiomatic expression used to describe a sudden burst of anger or losing control of one's emotions. Several antonyms or opposite phrases that express a calm or peaceful demeanor include keeping one's cool, staying composed, being tranquil, maintaining serenity, controlling one's temper, and remaining level-headed. These phrases signify a state of mind where an individual maintains self-control and keeps their emotions in check, even in stressful situations. Rather than responding impulsively or aggressively, individuals with these traits tend to approach challenging situations with a cool and collected mindset. Therefore, being composed and tranquil can positively impact an individual's relationships and professional life.