This is the 6380th most frequent Polish word.
busko
"Busko" is not a standalone word in Polish with a specific definition in English, but it may refer to "Busko-Zdrój," a town in Poland.
Here, 'Buska' is a reference to a place name, 'Busko-Zdrój', a resort town.
Pojechałem do Buska na spotkanie.
I went to Busko for a meeting.
The word 'Busko' refers to 'bus' but in a diminutive and possibly affectionate way.
Busko stoi na przystanku i czeka na pasażerów.
The bus is at the stop waiting for passengers.
Here 'busku' colloquially refers to privately-owned buses or minibuses, which are often used for local transport.