This is the 2145th most frequent Turkish word.
festivali
The Turkish word "festivali" means "festival" in English.
Here, "festivali" is used as a noun in possessive form, meaning "festival of." It specifies the type of festival.
Çocuklar, yaz festivali için heyecanlanıyor.
The children are excited about the summer festival.
In this sentence, "festivali" is still a noun in possessive form, pointing to "festival about/for art." It denotes a particular thematic festival.
Sanat festivali bu yıl İstanbul'da düzenlenecek.
The art festival will be held in Istanbul this year.
"Festivali" again is a noun in possessive form, referring to "music festival" and conveying the idea of a festival focused on music.