There are various synonyms for the term "shady business" which refer to unethical or illegal activities conducted by individuals or groups. Some of these synonyms include shady dealings, underhanded practices, unlawful practices, unethical behavior, crooked dealings, and shady transactions. These terms are often used in informal and colloquial language to describe various situations where individuals or organizations indulge in immoral and deceitful practices. Additionally, there are synonyms such as dubious practices, dodgy deals, and questionable behavior which also relate to the term "shady business". These words are often used to describe situations where people act in a manner that is suspicious or unethical, and it is important to be aware of them in order to avoid getting involved in such activities.