closed book, a

A secret, mystery, or puzzle, as in I can't figure her out; she's a closed book to me. This term alludes to information one can't obtain or comprehend (because the book is closed). [Early 1900s]

Common Names:

Name	Pronounced	Usage
Lacy	LAY-see	English
Kinga	KEEN-gah (Polish), KEEN-gaw (Hungarian)	Polish, Hungarian
Adelaida	-	Spanish, Hungarian
Eleanore	['elinə]
Egidio	-	Italian
Weldon	WEL-dən	English