Meditation is a mental process used to cultivate calm and insight.
Jack, a youth from Carbon Creek, Pennsylvania, preparing for college spent a lot of time at the library about places he liked to visit, including Tibet. While discussing meditation with T'Mir, Jack explained to her that in his readings, he learned that the Buddhist monks of Tibet meditate every day. (ENT: "Carbon Creek")
Meditation is used by Vulcans to calm and keep their tempestuous emotions under control as part of Surak's doctrine of Logic. Certain forms of intense meditation can be used to suppress the effects of Pon farr when a Vulcan male cannot return to its homeworld to take a mate. (VOY: "Blood Fever")
After the USS Voyager entered the starless region known as the Void in 2375, Tuvok began to meditate in the astrometrics lab before an image of a starfield. He explained to Seven of Nine that he imagined each star as a single thought. (VOY: "Night")