No, in the 10-14th centuries Hungarians called Eastern Slavs like this. It is originally a bastardized word for the Russians based on the misspelling. The term existed until 16th century and was used for Russia and Russians in Latin texts and then disappeared. It was also used by Germans for Baltic Christians until about that time.
It was resurfaced in the 19th century by Austro-Hungary to rally the West Ukrainians against the Russians as if they are different.
Your arguments so far:
* Claimed no one separated Ukrainians from Russians in 1920 when they arrived at Ellis Island - Proved you wrong by pointing to the US census.
* You pushed that date back to 1900. - Still wrong, as again demonstrated by the census.
Now you push that back saying the separation was only invented in the 19th century. The truth is back then it was a non-issue as Ukraine and Russia were not the same country and hadn’t been for centuries.
Here is a question: how many years before 1800 were Kiev and Moscow/Novgorod ruled by the same person? I think the answer will surprise you.