The phrase "are down mouth" means feeling sad or gloomy. There are several antonyms for this phrase, including "upbeat," "joyful," "happy," "cheerful," "blissful," "content," "satisfied," "ecstatic," and "exhilarated." When someone is "upbeat," they are feeling positive and optimistic, while "joyful" implies a sense of happiness and delight. "Happy" suggests a general feeling of satisfaction and contentment, while "cheerful" conveys a positive and optimistic outlook. "Blissful" suggests a state of complete happiness and contentment, while "content" implies a sense of satisfaction and peace.