This is the 581st most frequent Slovenian word.
njihov
"Their" (possessive pronoun).
The word "njihov" is used as a possessive pronoun referring to a plural subject (they/them), indicating ownership or association with the noun "car".
To je njihov avto.
This is their car.
The phrase "njihovih knjig" uses "njihov" in the genitive plural form to indicate possession of the noun "books."
Knjižnica je zbirka njihovih knjig.
The library is a collection of their books.
Here, "njihove" is the genitive plural form of "njihov," showing possession in relation to the plural noun "slike" (pictures).