"Blow top" is an idiom commonly used to describe an outburst of anger or frustration. Antonyms of this phrase include "calm," "cool-headed," "composed," and "collected." These words describe the opposite of losing control and becoming angry in a given situation. Instead, they suggest a sense of restraint and level-headedness, even in the face of challenging circumstances. These antonyms can be invaluable when trying to deescalate a tense situation or maintain poise under pressure. By remaining calm and composed, individuals can avoid "blowing their top" and instead find more constructive solutions to their problems.