Etymology

From Middle Mongolian ᠣᠷᠤᠰ ‎(orus) / Орос ‎(Oros, “Russia”), from Russian Росси́я ‎(Rossíja, “Russia”).

Mongolian does not allow word-initial r-, and regressive vowel harmony generated the prosthetic word-initial vowel, which is retained in Chinese as an extra syllable.

Pronunciation