Alien
From Tardis Wiki, the free Doctor Who reference
An alien is a general term for any entity which is not native to Earth. This can include both sentient and non sentient creatures, as well as most extraterrestrial robots. When on other planets, non-human creatures are still referred to as aliens by humans (though it should be the other way around).
Oddly enough, the Doctor referred to the Silurians as an alien race, despite the fact that they are native to Earth.