Quick-tempered people are known for their irritability, short fuse, and propensity to become angry easily. Some antonyms for the phrase quick-tempered would be level-headed, patient, calm, and composed. These individuals are less likely to react impulsively and respond to situations in a more thoughtful and rational manner. They tend to be more understanding, empathetic, and tolerant, which enables them to handle stressful situations with ease. Their temperament allows them to stay composed in difficult situations, and they do not take things personally. Overall, having a calm demeanor is a desirable characteristic that allows individuals to resolve conflicts amicably and maintain good relationships with others.