This is the 9343rd most frequent Russian word.
тадей
The word "тадей" does not have a direct meaning in Russian; it may be a name (Tadei) or a misspelling.
In this sentence, 'Тадей' is used as a proper noun, serving as the subject of the sentence. It refers to a person's name.
Тадей подошёл к столу, чтобы взять книгу.
Tadey approached the table to pick up the book.
Here, 'Тадей' functions as a possessive agent, indicating who brought the book. It's in the instrumental case to reflect its grammatical role.
Книга об истории была принесена Тадей.
The book about history was brought by Tadey.
In this example, 'Тадей' is used in the instrumental case ('Тадеем') to indicate the author of the story, showing action attributed to the person.