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
Philomena	fil-ə-MEEN-ə (English)	English, German, Late Greek
Hristo	-	Bulgarian, Macedonian
Emer	EE-mur	Irish, Irish Mythology
Barlow	['ba:ləu]
Mcfarland	[mək'fa:lənd]
Elkan	-	Hebrew