This is the 17874th most frequent Polish word.
ługańsku
"Ługańsku" is the locative case of "Ługańsk," meaning "in Luhansk," a city in Ukraine.
Used as the name of a place, Luhansk, in locative case to express the location where the action occurs.
Lubię spacerować po Ługańsku, szczególnie wiosną.
I like walking in Luhansk, especially during spring.
Again, used as the name of a place, in the locative case to describe the location of someone's residence.
W Ługańsku mieszkają moi znajomi.
My friends live in Luhansk.
Used in a question involving a place name, taking the locative case to describe the location related to the verb 'been'.