This is the 7499th most frequent Russian word.
джанкої
"Джанкой" is a town in Crimea; its name is of Turkic origin, meaning "spirit village" or "soul village."
Here, 'джанкои' is used as a proper noun referring to a geographic location.
Джанкои - это небольшой город в Крыму.
Dzhankoy is a small town in Crimea.
In this sentence, 'джанкое' is used to indicate a location where an action takes place, employing a locative case typical in Russian grammar.
Моя бабушка всегда покупает свежие овощи на рынке в Джанкое.
My grandmother always buys fresh vegetables at the market in Dzhankoy.
Here, 'джанкой' is used in instrumental case as part of the phrase indicating movement through the area.