The antonyms for the phrase "on bottom" are "on top," "higher up," and "above." These words describe a position that is above another object, location, or person. For example, a person can be on top of a hill or building, a bird can fly higher up in the sky, and a painting can be above the couch. The opposite of "on bottom" implies a sense of dominance, power, or superiority, as the person or object on top has a better vantage point and typically commands a greater level of attention or authority. In contrast, being on bottom can suggest vulnerability, weakness, or subordination.