The book became her secret friend.
Meaning: This means that she felt like the book was a close friend who she could share her secrets with.
Choice of Words: Became means to come to be or to change into a new state or condition. Secret means kept hidden or private. Friend is a person who you know and like and who you spend time with. When you put them together, "The book became her secret friend" means that the book changed into a hidden or private person who she liked and spent time with.
Alternative Expressions
Related Expressions