The term "wrong'un" is an informal British word used to describe someone who is untrustworthy or deceitful. There are several synonyms for this word, including rogue, scoundrel, trickster, cheat, fraudster, deceiver, and rascal. These words are often used interchangeably to describe individuals who engage in dishonest or unethical behavior. Other similar words that can be used to describe a "wrong'un" include charlatan, impostor, swindler, and con artist. These words all have a negative connotation and are typically used to describe individuals who are not to be trusted. When looking for alternatives to the word "wrong'un," it is important to consider the context and tone of the message being conveyed.