Misfeasor is a term that refers to someone who has committed an act that is considered illegal or improper. There are a variety of synonyms for this word, including wrongdoer, transgressor, offender, culprit, and delinquent. Other related terms include violator, lawbreaker, malefactor, and criminal. These words all similarly describe someone who has committed an unlawful or unethical act, and they can be used interchangeably depending on the context. It is important to note that the severity of the offense and legal implications can vary between these terms, but they all refer to someone who has acted in a way that is considered inappropriate or illegal.