There are several synonyms for the phrase "show the weakness in." These include "expose the flaw in," "reveal the vulnerability of," "highlight the deficiency in," "demonstrate the imperfection of," and "uncover the limitation in." Each of these alternative expressions emphasizes the idea of identifying or pointing out an area of weakness, whether it be in a product, argument, or individual. By using one of these synonyms, writers and speakers can add variety and nuance to their language while still communicating the same essential message. Additionally, shifting between different synonyms can help emphasize different aspects of the weakness being identified.