This article is from the Dune FAQ, by Alan Schwartz with numerous contributions by others.
Ordos is the name of an area in China, the origin of the Turks. It may
be related to the word "horde."
Answer courtesy of MtLoweMan
House Ordos is the third side (House Atreides and House Harkonnen being
the first two) you can play as in the Westwood computer games Dune II
and Dune 2000. House Ordos does not appear anywhere in Frank Herbert's
_Dune" novels. The name of the House appears in a list of Great Houses
under the entry "Great Houses" in "The Dune Encyclopedia", an article
written by Walter E. Meyers. In that article, they are listed as having
7 votes in the Landsraad (Atreides and Corrino having 10 each, Harkonnen
having 5), and their coat of arms is given as "Or two bones white per
saltire, in dexter chief entwined with ivy vert." This translates to
"Two white bones crossed over a golden background, with the upper right
part entwined with green ivy." Heraldic right is left to those looking
at the shield. The Ordos coat of arms in the computer games, with a
snake and a book, is the coat of arms of House Wallach. No further
information about them is given anywhere. The details of their
background were made up for the computer games.
 
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