This is the 7633rd most frequent Russian word.
жансаи
The word "жансаи" does not appear to have a clear definition in standard Russian. It might be a proper noun (e.g., a name) or a non-standard/local term.
Here, 'Жансаи' functions as a proper noun, likely a name, and acts as the subject of the sentence.
Жансаи мечтает изучить различные языки.
Zhansai dreams of learning various languages.
In this sentence, 'Жансаи' is used in the accusative case to denote the direct object of the action.
Мы пригласили Жансаи на наше культурное мероприятие.
We invited Zhansai to our cultural event.
'Жансаю' in this sentence is used in the dative case, indicating the recipient of gratitude.