a closed book

a closed book

a thing of which you have no knowledge or understanding

1944 - Frank Clune - The Red Heart - The desert is an open book to the man of the Vast Open Spaces, but to the schoolmaster it was a closed book.

Related Idioms :

behind closed doors

(of an action) done in a secretive or furtive way hidden from public view

a closed book :

a closed book To HOME PAGE

Idioms Index – Previous Page

Related Links : a closed book