This is the 7762nd most frequent Russian word.
изюмского
"Изюмского" is the genitive or adjectival form meaning "of Izium" or "Izium's," referring to something related to the city of Izium in Ukraine.
The word 'изюмского' is used as an adjective derived from 'Изюм', referencing the origin or style of the bread.
Я купил пакет изюмского хлеба.
I bought a loaf of Izum-style bread.
'Изюмского' functions as a possessive adjective, indicating the origin of the artist from Izum.
Эта коллекция картин принадлежит изюмского художника.
This collection of paintings belongs to an artist from Izum.
In this sentence, 'изюмского' describes the art associated with or originating from Izum, classifying the type of festival.