This is the 9217th most frequent Russian word.
смольского
"Смольского" is a genitive or adjective form related to "смольский," which typically refers to something associated with tar ("смола") or a proper name. Context determines its exact meaning.
The word 'Смольского' here is used as a proper noun in the genitive case, indicating possession or attribution.
Я восхищаюсь писателем Смольского.
I admire the writer Smolsky.
The word 'Смольского' functions as an adjective form (or derived from a proper noun in attribution) in the genitive case referring to the museum associated with Smolsky.
Картина находится в музее Смольского.
The painting is located in the Smolsky museum.
The word 'Смольского' is again in the genitive case, commonly used to denote possession or association, referring to the house belonging to Smolsky.