Show out is a phrase used to describe when someone is acting in a way that is flashy or attention-seeking. Some synonyms for show out include showing off, flaunting, and performing. Other options include boasting, parading, and demonstrating. When someone is trying to impress, they may be said to be displaying, exhibiting, or showcasing their abilities. If someone is acting ostentatiously, they may be accused of grandstanding or posturing. In a more casual context, people may refer to someone as hamming it up or putting on a show. Whatever the terminology, the message remains the same: when someone is 'showing out,' they are drawing attention to themselves.