This is the 386th most frequent Russian word.
документов
Genitive plural of "документ" meaning "documents."
The word 'документов' is in the genitive plural form, showing possession or association and is the object of the action 'проверки'.
У меня есть время для проверки документов.
I have time to review the documents.
Here, 'документов' again is in the genitive plural to indicate possession or association with the delivery described in the sentence.
Мы ждём доставки важных документов.
We are waiting for the delivery of important documents.
In this example, 'документов' is in the genitive plural, indicating the documents to which the pages belong.