Resurrection

Resurrection is the process by which the deceased are returned to life through various external means.

Elixir of Life
The Sisterhood of Karn has been shown to be able to resurrect a Time Lord using their Elixir of Life. However, this is a temporary measure and only brings back the resurrected for a few minutes. Another dose of Elixir can be used to induce and control a regeneration, bringing the Time Lord back completely. (TV: The Night of the Doctor)

Bad Wolf entity
The Bad Wolf entity has shown the ability to resurrect the dead. However, as Rose Tyler didn't possess complete control over this power, she brought the person back forever. (TV: The Parting of the Ways, Utopia)

Time Lords
The Time Lords have been stated to have the ability to resurrect deceased Time Lords. (TV: The Sound of Drums)

Potions of Life
Before his Harold Saxon incarnation was killed, the Master detailed the "potions of life" to the Cult of Saxon in their Book of Saxon. Combined with the Master's ring and his biometric imprint, this was capable of resurrecting the Master even after cremation. However a "potion of death" could interrupt the resurrection and make it go wrong. (TV: The End of Time)