俄罗斯(é luó sī) - Russia in Mandarin

俄罗斯 (É luó sī) is Russia. The three characters carry no meaning of their own; they were picked for sound, and the odd opening 俄 comes from Mongolian, which could not begin a word with r and prefixed a vowel to Rus before the name reached Chinese.

The family of related words is worth learning together. The language is 俄语 or 俄文, a Russian person is 俄罗斯人, and anything Russian in a compound shortens to a single 俄: 俄军 for the Russian army, 中俄关系 for Sino-Russian relations. That abbreviation to one character is standard practice for country names.

The trap is 俄国, which also means Russia but leans historical. It is the usual choice for the Tsarist empire and older writing, while 俄罗斯 is the modern state and the neutral everyday choice. If you are unsure, 俄罗斯 is safe.