Where does “鄂爾多斯” come from?

鄂爾多斯 (Chinese) comes from Mongolian ᠣᠷᠳᠣᠰ.

Ancestry of “鄂爾多斯”, step by step

Step	Language	Word	Meaning
1	Mongolian	ᠣᠷᠳᠣᠰ	—