Goon is a pejorative noun used to term lackeys and help of unsavory sorts, akin to thug or flunky. It derived from the word "gooney", which refers to something or someone silly, foolish, and awkward, and was popularized with the famous E.C. Segar comic serial Popeye, where goons were a race of giant barbaric brutes who served the villainous Sea Hag.
Usage
See Special:Whatlinkshere/Etymology:Goon for a list of articles using this term.