This is the 2273rd most frequent Turkish word.
başvurusunu
"Başvurusunu" means "his/her/its application" in English.
In this sentence, 'başvurusunu' refers to Ali's application for a university.
Ali, üniversiteye başvurusunu tamamladı.
Ali completed his application to the university.
Here, 'başvurusunu' denotes Merve's job application form.
Merve, iş başvurusunu imzalayıp teslim etti.
Merve signed and submitted her job application.
In this example, 'başvurusunu' is used for the student's application for a scholarship.