On “Seinfeld,” George Costanza says he would call himself “Buck Naked” if he became a porn star. The joke appears in “The Outing,” the Season 4 episode in which a reporter mistakenly assumes Jerry and George are a gay couple.
George introduces the name while chatting with Jerry, presenting it as a clever stage name. Jerry immediately recognizes the obvious pun: “Buck Naked” sounds like “buck naked,” meaning completely nude. The humor comes from George’s confidence that he has invented a memorable adult-film persona, even though the name is almost comically direct.
A common mix-up is attributing the line to “The Mango,” a Season 5 episode that also discusses George’s sexual anxieties and includes a related reference to “Buck.” However, the full porn-star-name exchange is most directly associated with “The Outing.” Another occasional confusion is giving the name to Jerry; Jerry is the character who responds to George’s idea, while George is the one who claims the alias.