"Sheisty" is an informal term that describes someone who is deceitful, dishonest, or untrustworthy. Synonyms for "sheisty" include shady, sketchy, tricky, sneaky, dishonest, conniving, sly, fraudulent, and deceitful. These words are often used to describe individuals who engage in questionable or unethical behavior, such as spreading rumors, lying, cheating, or stealing. While these terms have similar meanings, they may also have slightly different connotations depending on the context in which they are used. Regardless of the word choice, someone who is described using these synonyms is generally viewed as someone who cannot be relied upon to act with integrity or honesty.