This is the 611th most frequent Czech word.
jejíž
"Jejíž" means "whose" (feminine singular, relative pronoun).
Used to indicate possession or attribution related to a feminine noun (author of the book).
To je kniha, jejíž autor získal Nobelovu cenu.
This is the book whose author won the Nobel Prize.
Refers to a relationship involving a feminine noun (the girlfriend in this case).
Viděl jsem dívku, jejíž přítel je známý hudebník.
I saw the girl whose boyfriend is a famous musician.
Denotes ownership or a defining characteristic related to a feminine noun (the garden's flowers).