Antonyms for the phrase 'most wound up' would be calm, relaxed, composed, collected, cool-headed, and serene. These terms describe a state of peace and tranquility, opposite to the agitation and restlessness implied by 'most wound up.' A person who is calm and relaxed is at ease and fully in control of their emotions, while someone who is wound up is tense, anxious, and highly strung. Being able to maintain a calm and composed demeanor is highly valued in many aspects of life, including personal relationships, work, and social situations. By practicing relaxation techniques and adopting a positive mindset, one can learn to stay calm and centered even in stressful situations.