This is the 8509th most frequent Russian word.
новая
"New."
The word 'новая' describes the condition or state of being new of the noun 'книга' (book), agreeing in gender (feminine), number (singular), and case (nominative).
У меня есть новая книга.
I have a new book.
The word 'новую' is the accusative case form of 'новая,' aligning with the feminine singular noun 'машину' (car) as the direct object of the verb 'купила' (bought).
Она купила новую машину.
She bought a new car.
The word 'новое' is the neuter form of the adjective 'новый/новая,' used here to modify the neuter singular noun 'здание' (building).