This is the 6624th most frequent Russian word.
kiev
"Kiev" is the former name of the capital city of Ukraine, now officially called "Kyiv."
'Киев' is used as a proper noun referring to the city of Kyiv, geographical context.
Киев - это столица Украины.
Kyiv is the capital of Ukraine.
'Киев' is used as a place of interest, indicating one's desire to travel to this city.
Я хотел бы посетить Киев летом.
I would like to visit Kyiv in the summer.
'В Киеве' ('In Kyiv') demonstrates the locative case, showing the location of actions within the city.