This is the 15526th most frequent Polish word.
starego
"Starego" means "old" in the masculine singular genitive or accusative form in Polish.
The word "starego" is used as a genitive case adjective modifier agreeing with "domu" in describing an old house.
Widzę szafę starego domu.
I see a wardrobe of an old house.
Here, "starego" refers to "znajomego", functioning as a genitive case adjective describing an old friend, where "znajomego" is the noun in genitive.
Dostałem książkę od starego znajomego.
I received a book from an old acquaintance.
In this sentence, "starego" modifies "albumu" as a genitive case adjective, referring to the album as being old.