The Bones Reference
Dr. McCoy’s nickname “Bones” is likely from two sources. First, it may have been derived from the old-fashion idiom “sawbones” for a doctor. In Star Trek 2009, Kirk called McCoy “Bones” after McCoy revealed his divorce left him just his “bones.”
Source: Syfy
Random fact: an alternate reality was established in Star Trek 2009, in which Vulcan was destroyed by the Romulan Captain Nero in 2258. As Spock said, “He is a particularly troubled Romulan.”