Definition

1. Noun:
   • Something that baffles understanding and cannot be explained: A subject, matter, or person that is completely incomprehensible, mysterious, or unknowable to someone.

Usage

• The term "closed book" is used to describe a topic or person one finds impossible to understand. It emphasizes a total lack of knowledge or insight.
• It is typically used in the construction: "X is a closed book to me" or "X remains a closed book."

Examples

• Noun:
  • Advanced mathematics is a closed book to me. (I find advanced mathematics completely incomprehensible.)
  • Her motives for leaving remain a closed book. (Her reasons for leaving are still completely mysterious and unknowable.)
  • I've tried to understand quantum physics, but it's a closed book. (I have attempted to understand quantum physics, but it remains utterly baffling.)

Advanced Usage

• "to be a closed book": To be an utterly incomprehensible subject or person.
  • The inner workings of the government are a closed book to most citizens.
• "to remain a closed book": To continue to be mysterious or unfathomable.
  • Despite years of study, ancient Egyptian religion remains largely a closed book.

Variants and Related Words

• Enigma (n): Something or someone that is mysterious, puzzling, or difficult to understand.
• Mystery (n): Something that is difficult or impossible to understand or explain.

Synonyms

• Puzzle: Something that confuses or baffles.
• Conundrum: A confusing and difficult problem or question.
• Impenetrable: Impossible to understand.

Idioms and Phrases

• A sealed book: This is a very close synonym, also meaning something impossible to understand.
  • The legal jargon in the contract was a sealed book to the layperson.

Noun

1. something that baffles understanding and cannot be explained
   • how it got out is a mystery
   • it remains one of nature's secrets