The phrase "bad actor" refers to someone who behaves unprofessionally, deceitfully or dishonestly. When trying to describe someone who exhibits these negative traits, there are a variety of synonyms to choose from. Some alternatives to "bad actor" include "charlatan," "imposter," "rogue," "swindler" or "fraud." Another term commonly used is "black sheep," which refers to someone who is disreputable or troublesome. Other potential phrases to replace "bad actor" might be "dishonest practitioner," "untrustworthy actor," or "fake performer." Regardless of which synonym is selected, the meaning remains the same - a person who is not to be trusted or relied upon.