This is the 886th most frequent Spanish word.
infantil
Related to childhood or children; childish.
In this sentence, "infantil" is used as an adjective to describe the type of book. It indicates the book is intended for children.
Ella compró un libro infantil para su sobrino.
She bought a children's book for her nephew.
Here, "infantil" is used as an adjective to describe behavior. It is metaphorically used to indicate immaturity.
El comportamiento infantil del equipo fue decepcionante.
The childish behavior of the team was disappointing.
In this sentence, "infantil" describes the themes, meaning they are child-related or suitable for children.