Variags
The Variags were a little-known people who dwelt in the land of Khand, east of Mordor, at the time of the War of the Ring. They were allied to Sauron, and their warriors were seen at the Battle of the Pelennor Fields.
Etymology
Variag is a word of a Harad language[1], but its meaning is unknown.
Inspiration
Variag is a Slavic word derived from Norse Varingar "mercenary people" (vár "contract"). The Norse root indicates that perhaps Tolkien intended Variag to be a "translated" Northern Mannish word.
Also, the meaning suggests that the Variags of Khand were not an ethnic group but a kind of elite mercenaries or corps in service of Mordor.
Portrayals in adaptations
In Peter Jackson's The Return of the King, Variags were depicted as a cross between feudal Japanese and Mongolians, with such objects as the vertical flag attached to the back of the warrior, except that the Variag chieftains rode in chariots.