Savage

A savage was member of a group living outside an unnamed city in the future. Those inside the city were called "Elders", who coined the pejorative phrase against their planet's co-inhabitants. The Elders treated the "savages" contemptuously by draining them of their life force. The real name of the "savages" was unknown. (DW: The Savages)

The Doctor mused to himself that Leela was a "savage" after she had left him on Gallifrey, but it was likely used in more of an ironic or anthropological sense than as an insult or a reference to this particular unrelated group. (DW: The Invasion of Time)