Cloning tank

Cloning tanks were vats in which clones might be grown.

Compared to the Time Lords' own looms, (PROSE: Lungbarrow, The Book of the War) cloning tanks were decried by members of their kind, such as Sergeant-Instructor Littlejohn, as primitive. Littlejohn was surprised to learn that the Firmament, their counterparts in the 10,000 Dawns, used simple cloning tanks both for reproduction and resurrection, instead of something more sophisticated. (PROSE: The Gendar Conspiracy)

Cloning tanks were used by the Sontarans to create temporary clones of enemies. (TV: The Sontaran Stratagem)

Behind the scenes
Though not used on-screen in The Sontaran Stratagem, the term is used on the BBC website, in reference to concept art of the tank.