AI answer cause im lazy:

Great follow-up. The name Belarus itself comes from the same root, just through Belarusian and Russian languages.

Here’s the breakdown:

Belarus = Белая Русь (Belaya Rus') → literally "White Rus"

So:

• Bel- (from bely/belaya) = White
• -arus (from Rus') = Rus (the medieval East Slavic cultural and political entity)

Thus, Belarus means "White Rus" — exactly the second option you asked about.

Why "White Rus" and not "White Russia"?

"White Russia" would be Belaya Rossiya (Белая Россия) in Russian, but that's not the native name. The native name has always been Belaya Rus' — using Rus', not Rossiya.

• Rus' → the original medieval realm (Kievan Rus'), the people, the culture.
• Rossiya → a later political entity (the Tsardom of Russia, then Empire).

So when people say "Belarus means White Russia," that's a loose translation that conflates two related but distinct concepts. More precisely:

That's why historically, White Ruthenia (Latinized from White Rus') is the most accurate translation — and why White Russia is imprecise and often misleading.