The phrase "square peg round hole" is often used to describe a misfit or someone who doesn't belong. There are several synonyms that can be used in place of this phrase, including "misfit," "nonconformist," and "odd man out." Other alternatives include "mismatch," "incompatible," and "out of place." Each of these phrases conveys a similar message, and they can be used interchangeably depending on the context in which they are being used. By using a different synonym to describe a misfit, you can add variety to your writing and communicate your message in a clearer, more creative way.