There are several synonyms for the term "untrustworthy person." Some of these include: unreliable, deceitful, dishonest, scammer, fraud, swindler, and charlatan. An untrustworthy person is someone who can't be trusted or relied upon. Whether they are manipulative, untruthful, or simply have a pattern of breaking promises, an untrustworthy person can cause significant harm to those around them. It's important to be able to recognize the warning signs of an untrustworthy person and take steps to protect yourself and your loved ones. This may include being cautious around new acquaintances or seeking out professional help if you suspect someone is being untruthful or deceitful.