This is the 4334th most frequent Russian word.
библиотекой
"Библиотекой" means "library" in the instrumental case in Russian.
The word 'библиотекой' is used in the instrumental case to indicate the means or object of inspiration.
Я всегда вдохновляюсь этой библиотекой.
I am always inspired by this library.
The word 'библиотекой' is in instrumental case showing the involvement or association.
Он занимается в библиотекой каждую субботу.
He studies at the library every Saturday.
Here, 'библиотекой' describes the positional context in relation to the tour.