This is the 9226th most frequent Russian word.
соборной
"Соборной" means "cathedral" (adjective) or "conciliar," relating to a council or assembly.
The word "соборной" is used here as an adjective describing a street, implying its association with a cathedral or its grandeur, suggesting historical significance.
Соборной улице присуща историческая атмосфера.
Sobornaya Street has a historical atmosphere.
In this context, "соборной" modifies "площади" (square), indicating it is a square associated with or named after a cathedral, emphasizing its central and important communal role.
На соборной площади собрались жители города.
The townspeople gathered on the cathedral square.
Here, "соборной" describes a school associated with a cathedral, likely referring to its ecclesiastical or spiritual educational focus.