This is the 448th most frequent Greek word.
παιδιού
"παιδιού" means "of a child" or "child's" (genitive singular form).
In this sentence, 'παιδιού' is the genitive singular form of 'παιδί', showing possession.
Το παιχνίδι του παιδιού είναι στο τραπέζι.
The child's toy is on the table.
Here, 'παιδιού' is the genitive singular form of 'παιδί', used to introduce a relation or subject of the story.
Αυτή είναι η ιστορία ενός παιδιού που αγάπησε τα βιβλία.
This is the story of a child who loved books.
In this sentence, 'παιδιού' is the genitive singular form of 'παιδί', indicating an attribute or characteristic (the voice belongs to the child).