This is the 10346th most frequent Turkish word.
biliyordur
"He/she probably knows."
In this sentence, 'biliyordur' expresses a possibility or assumption that Ahmet is aware of the meeting time.
Ahmet toplantının saatini biliyordur.
Ahmet might know the time of the meeting.
Here, 'biliyordur' conveys the speaker's assumption or a likelihood that the person knows the location of the book.
O kitabı nerede bulabileceğini biliyordur.
He/She probably knows where to find that book.
In this example, 'biliyordur' is used to imply a probable understanding or knowledge that the subject has regarding the matter described.