This is the 665th most frequent Russian word.
родителей
"Parents."
The word 'родителей' is used in the prepositional case when following the preposition 'о' which governs its discussion about 'parents'.
Мы говорили о наших родителях.
We were talking about our parents.
The word 'родителей' is in the genitive case related to the possessive construction 'moих родителей' describing ownership.
У моих родителей есть большая коллекция книг.
My parents have a large collection of books.
The word 'родителей' is used in the accusative case as the direct object of the verb 'встретил'.