Homeworld

The word "homeworld" referred to the planet, the "home planet", or in some cases moon, on which a particular species originated and developed their cultures and their histories on. In some cases, more than one intelligent species originated from the same planet. (TV: Doctor Who and the Silurians) In order for a celestial body to be a homeworld, it did not have to be the site where a species evolved, but one that had been adopted.

Earth was the homeworld of Earth Reptiles, such as Silurians and Sea Devils, and humanity. (TV: Doctor Who and the Silurians) In Pete's World, Earth was the homeworld of a race of Cybermen. (TV: Rise of the Cybermen, Doomsday) The Second Doctor referred to Earth as the mother world in relation to the early colonisation of the solar system. (PROSE: The Wheel of Ice)

As the Twelfth Doctor observed, Cybermen rose on many worlds as a result of parallel evolution wherever there were people, including Mondas, Telos, Earth, Planet 14, and Marinus. (TV: The Doctor Falls)

According to the Sixth Doctor, the Cybermen who inhabited Telos were originally Mondasians, all but wiping out the indigenous population, the Cryons. (TV: Attack of the Cybermen) According to one account, he also found Mondas, Planet 14, and Marinus to be the same planet, the Voord having evolved into Cybermen. (COMIC: The World Shapers)

Skaro was the homeworld of the Thals and Kaleds, later the Daleks. (TV: Genesis of the Daleks)

Gallifrey was the homeworld of the Time Lords, (TV: The Time Warrior) and, due to its important role in the Spiral Politic, it was frequently known as simply "the Homeworld". (PROSE: The Book of the War) Residents of the City of the Saved often called it "the Houseworld". (PROSE: Of the City of the Saved...)

Manussa was the homeworld of the Manussan and Sumaran Empires, both of which collapsed. (TV: Snakedance)

Raxacoricofallapatorius was the home planet of the Raxacoricofallapatorians. (TV: World War Three) Its twin planet was Clom, birthplace of the Abzorbaloff. (TV: Love & Monsters)

Pyrovillia was the homeworld of the Pyroviles. (TV: The Fires of Pompeii)

The Sense Sphere and Ood Sphere were the respective homeworlds of the Sensorites and the Ood. (TV: The Sensorites, Planet of the Ood)

Replacement
In the event of the loss of one's homeworld, a new one would sometimes be settled. In light of Earth Death, humanity chose a planet in the galaxy M87 as New Earth, due to it having the same size, air and orbit as the original Earth. Humans shared this planet with new humans, Catkind, (TV: New Earth) Macra, (TV: Gridlock) tree people of Cheem, indigenous Termitons, (AUDIO: Death in the New Forest) Birdkind, solar bears, sky penguins, (AUDIO: The Skies of New Earth) Scorpionkind and Lizardkind. (AUDIO: The Cats of New Cairo)

To replace their homeworlds, the Daleks and the Cybermen established New Skaro (PROSE: Birthright) and New Mondas respectively. (PROSE: Legacy, Theatre of War)