This is the 423rd most frequent Ukrainian word.
їхній
"Their" (possessive pronoun).
In this case, 'їхній' relates to the possession of 'сюжет' (their plot), highlighting the shared aspect among the subjects of interest.
У мене є книга, їхній сюжет дуже цікавий.
I have a book; their plot is very interesting.
The word 'їхній' functions as a possessive pronoun indicating ownership in the third person plural for the noun 'будинок'.
Це їхній будинок.
This is their house.
Here, 'їхній' refers to the ownership of 'садок', emphasizing the associate's value or characteristic further described in the sentence.