noun
subordinate; underling; henchman; minion
Refers to someone who works under another's orders, often with a nuance of being a follower in a hierarchy, sometimes with a negative connotation of being a mere tool.
彼はボスの手下として働いている。
He works as a subordinate of the boss.
悪者の手下たちが町を荒らした
The villain's henchmen ravaged the town.
部下 is a neutral term for a subordinate in an organization, while 手下 often implies a closer, more personal follower, sometimes with a negative or informal nuance.
Compound of 手 (hand) and 下 (under), literally 'under one's hand', referring to someone under one's control.