|a person or thing without secrecy or concealment that can be easily known or interpreted|
|Main Entry:||open book|
|Part of Speech:||n|
|Definition:||something or someone that is easily understandable; something that is very clear; someone who conceals nothing|
|Example:||Her life is an open book.|
Something or someone that can be readily examined or understood, as in His entire life is an open book. This metaphoric expression is often expanded to read someone like an open book, meaning "to discern someone's thoughts or feelings"; variations of this metaphor were used by Shakespeare: "Read o'er the volume of young Paris' face," (Romeo and Juliet, 1:3) and "O, like a book of sport thou'lt read me o'er" (Troilus and Cressida, 4:5). [Mid-1800s] For an antonym, see closed book.