This is the 7059th most frequent Russian word.
белгородскую
"Белгородскую" translates to "Belgorod" in its adjectival form, meaning "related to Belgorod," a city in Russia.
Here, 'Белгородскую' is used as an adjective in the accusative case when modifying the noun 'область' (region).
Я посетил Белгородскую область в прошлом году.
I visited the Belgorod region last year.
In this sentence, 'Белгородской' is used in the genitive case to indicate the origin of the region in relation to the student.
Студент из Белгородской области выиграл в конкурсе.
A student from the Belgorod region won in the competition.
'Белгородскую' is used in the accusative case again, but with the preposition 'в' to indicate the destination of travel towards the region.