This is the 10848th most frequent Polish word.
dziwna
"Strange" or "weird."
Here, 'dziwna' describes the unusual or peculiar nature of the book. It's an adjective modifying the noun 'książka'.
Ta książka jest naprawdę dziwna.
This book is really strange.
In this sentence, 'dziwną' is used in a feminine singular accusative form to describe a peculiar or odd person.
Zauważyłam dziwną osobę w parku.
I noticed a strange person in the park.
The word 'dziwny' (male form) illustrates the adjective adapting to the described noun, 'sposób', pointing to an unconventional pattern of thinking.