permission to publish a book, granted by an official censor who, upon examining it, has certified that it contains nothing contrary to faith or morals.
Origin
1885-90; < Latin: literally, nothing stands in the way
British Dictionary definitions for nihil obstat
nihil obstat
/ˈɒbstæt/
uknown
1.
the phrase used by a Roman Catholic censor to declare publication inoffensive to faith or morals