The antonyms for the phrase "most down-in-mouth" are cheerful, optimistic, elated, joyful, and upbeat. These words represent the exact opposite of feeling low, distressed, or disheartened. When somebody is feeling down-in-mouth, they are experiencing a state of gloom and despair. It is essential to focus on the positive aspects of life and try to find happiness, no matter the situation. Being cheerful or optimistic can help an individual develop a better outlook on life, feel confident, and achieve their goals. Adopting an upbeat attitude and striving towards positivity can have a significant impact on one's mental health and well-being, leading to a happier, more fulfilling life.