This is the 10837th most frequent Polish word.
dziewiąta
"Ninth" or "9 o'clock" (depending on context).
In this sentence, 'dziewiąta' refers to the ordinal number indicating the time (ninth hour).
Dziewiąta godzina to czas, kiedy zaczynam pracę.
The ninth hour is the time when I start work.
Here, 'dziewiąta' is used to denote the ordinal position of the book (ninth book).
To już dziewiąta książka, którą przeczytałem w tym roku.
This is already the ninth book I have read this year.
In this case, 'dziewiąta' describes the name of a street (ninth street), being a part of the proper noun.