This is the 402nd most frequent Azerbaijani word.
özünün
"Özünün" means "of oneself" or "one's own" in English.
This use of 'özünün' emphasizes possession, highlighting that the book belongs to him/her specifically.
Özünün kitabını masanın üstündə qoydu.
He/She put his/her book on the table.
Here, 'özünün' is used for self-referencing, referring back to the subject to stress individual perspective.
Mənə dediyinə görə, özünün bu işlə bağlı heç bir fikri yoxdur.
According to what he/she told me, he/she has no opinion about this matter.
In this context, 'özünün' reinforces the subject's direct agreement or involvement in the statement.