This is the 415th most frequent Swedish word.
vars
"Vars" means "whose" in English, used to indicate possession.
"Vars" is a relative pronoun that connects "hunden" (the dog) to its attribute "päls" (fur).
Det är hunden vars päls är vit.
It is the dog whose fur is white.
Here, "vars" indicates possession, linking "hus" (house) to "tak" (roof).
Hon har ett hus vars tak är blått.
She has a house whose roof is blue.
In this sentence, "vars" shows the relationship between "park" (park) and "gräsmatta" (lawn).