This is the 8601st most frequent Russian word.
омску
"Омску" is the dative form of "Омск," the name of a city in Russia, meaning "to Omsk" or "for Omsk."
The word 'Омску' is in the prepositional case, which is used after the preposition 'в' to indicate location.
Я живу в Омску.
I live in Omsk.
The word 'Омску' is in the accusative case, typically used with 'в' to indicate direction or destination.
Мы едем в Омску на выходные.
We are going to Omsk for the weekend.
Here, 'Омску' is in the prepositional case associated with 'в' to specify a location.