There are several synonyms for the phrase "unsuited to the occasion." The first is "inappropriate," which is often used to describe clothing or behavior that does not match the expected norms of a certain event or setting. Another synonym is "incongruous," which implies a lack of harmony or coherence between different elements. "Mismatched" is another synonym that is often used to describe items, but can also be used to describe behavior or attitudes that do not fit the context. Other synonyms include "ill-fitted," "inapt," "unfitting," and "mismated." Each of these words can be used to convey a sense of something not being right or suitable for a particular occasion or context.