The antonyms of "be down mouth" dominate the positive aspects of mood and attitude. The opposite of being down mouth is optimism, positivity, hopefulness, and cheerfulness. One can be upbeat, lively, in good spirits, or high-spirited, which indicates a positive and happy demeanor. When someone is excited, enthusiastic, or content, they show nothing in common with being down mouth. Additionally, if you find a purpose or meaning in life, you are more likely to be satisfied and fulfilled, which is an antonym for the phrase. In general, opposites of being down mouth are uplifting and joyful emotions that everyone desires to experience.