Dr. Leonard McCoy forms the third part of Star Trek’s “holy trinity,” along with Captain Kirk and Mr. Spock. He’s also the only one of the three with a nickname: “Bones,” a references to his role profession as a physician. The The 2009 film reboot was very specific about the origin of McCoy's nickname, but the original character never received an official explanation. It was part of the original concept of Star Trek – predating even the character of Leonard McCoy – and was another early sign of the kind of attention to detail that made the show a classic.

Roddenberry’s original pitch for the show included a specific reference to a doctor named “Bones.” It wasn’t Dr. McCoy, but instead Philip Boyce (played by veteran actor John Hoyt), who served under Christopher Pike in "The Cage," and who was replaced, along with most of the rest of the cast, for the show’s second pilot. Nevertheless, the nickname transferred over, and was used in almost every episode when Kirk referred to his chief medical officer. Clearly, it held some especial importance to creator Gene Roddenberry.

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Spock, Kirk and McCoy on Star Trek: The Original Series

“Bones” is short for “sawbones,” a term from the early 19th century that referred to a doctor’s often-gruesome practice of amputating injured limbs. The implications provide a great deal of character development in a single word. In the first place, it suggests the Enterprise’s mission is a dangerous one, akin to combat, and that the ship’s surgeon is there to repair injuries as much as study new diseases or find new medicines.

But it also suggests something about the character himself, a self-described “country doctor” who can be cantankerous and difficult at times. The “sawbones” name suggests a figure devoted to “practical” medicine, who does what works without necessarily following medical procedure. It’s very much in keeping with McCoy. In fact, before Star Trek, actor DeForest Kelley, like many of his fellow cast members, was largely known for his roles in Westerns (Gunfight at the O.K. Corral, Warlock, Death Valley Days), the predominant TV and film genre of the era. So, a gruff country doctor was certainly in keeping with his onscreen persona. And Roddenberry, who famously pitched Star Trek to NBC executives as "Wagon Train to the Stars," was no stranger to Westerns, having written for such TV series as Have Gun - Will Travel, Jefferson Drum and The Virginian.

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J.J. Abrams’ Star Trek reboot was more explicit about the nickname, however. In a conversation with Kirk (Christopher Pine) on their way to Starfleet Academy, McCoy reveals the only reason he’s joining Starfleet is because he lost everything in a divorce. “All I got left is my bones,” he mutters before offering Kirk a drink. In the DVD commentary for the film, Abrams claims the moment was improvised by Karl Urban, a longtime Trek fan.

It’s unclear whether this explanation applies to the Prime Universe’s Bones, but it’s certainly in keeping with the character’s personality: contentious, passionate, grumpy, and forced into a vessel he considers less than safe by circumstance. Either way, it does the same job as the Prime Universe’s nickname by putting a human face on the character and allowing audience members to better identify with life aboard a 23rd century starship.

There is no official word on whether Boyce will appear in Star Trek: Strange New Worlds, along with the rest of Pike’s crew, or whether the show will address his nickname of “Bones” if he does. Given how closely the name is associated with McCoy at this point, it seems unlikely. Roddenberry’s commitment to detail paid off in an iconic character, and the nickname remains an inseparable part of that package.

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