This is the 523rd most frequent Lithuanian word.
pirmoji
"Pirmoji" means "the first" in English (feminine form).
Here, 'pirmoji' is a feminine singular nominative form of 'first' used as an ordinal number describing position.
Ji buvo pirmoji, kuri atėjo į klasę.
She was the first one to enter the classroom.
In this sentence, 'pirmoji' modifies the noun 'knyga' (book) in terms of position in a series, showing possession and served with its feminine subject.
Mano pirmoji knyga buvo apie istoriją.
My first book was about history.
Here, 'pirmoji' functions in its adjective form to describe 'vieta' (place), emphasizing its rank or numeric position in a competition.