A henchman is a loyal employee, supporter, or aide to some powerful figure engaged in nefarious or criminal enterprises. Henchmen are typically relatively unimportant in the organisation: minions whose value lies primarily in their unquestioning loyalty to their leader. The term henchman is often used derisively, or even comically, to refer to individuals of low status who lack any moral compass of their own.
The term henchman originally referred to one who attended a horse for their employer, that is, a horse groom. Hence, like constable and marshal, also originally stable staff, henchman became the title of a subordinate official in a royal court or noble household.