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
Destiny	DES-tə-nee	English
Amina	-	Bosnian, Arabic
Irinei	-	Russian
Miroslav	mee-rah-SLAHF (Russian)	Czech, Slovak, Russian, Serbian, Croatian, Slovene, Bulgarian, Macedonian, Medieval Slavic
Shantae	shahn-TAY	English (Rare)
Glenn	GLEN	Scottish, English