The phrase "am down in the mouth" is an informal expression that means to feel sad, depressed or dejected. The antonyms for this phrase would be "happy," "content," "elated," "upbeat," and "cheerful." When we are "down in the mouth," we often have a negative mindset and a lack of motivation. Therefore, it is crucial to find ways to stay positive and focused on the bright side of things. Listening to uplifting music, spending time with loved ones, pursuing hobbies or interests, and practicing gratitude and mindfulness are some ways to shift our mood and bring more positivity into our lives.