This is the 8615th most frequent Russian word.
оренбургский
"Oренбургский" means "Orenburg-related" or "pertaining to Orenburg," a city in Russia.
The word 'оренбургский' in this context describes the origin of the shawl, specifying that it comes from Orenburg.
Я купил красивый оренбургский платок.
I bought a beautiful Orenburg shawl.
The word 'оренбургские' here modifies 'степи', indicating the geographical region associated with the steppes.
Оренбургские степи известны своей красотой.
The Orenburg steppes are known for their beauty.
In this sentence, 'оренбургским' describes the type of evening, implying it is in or characteristic of Orenburg.