Nihil obstat (Latin for 'nothing hinders' or 'nothing stands in the way')[1] is a phrase traditionally used by Catholic Church authorities to formally declare that there is no objection to the publication of a book.
[2] The Censor Librorum is delegated by a bishop to review the text in question over approximately two months.
[3] If an author is a member of a religious institute, such as a monastery, and the book concerns religion or morals, then canon law further requires the imprimi potest ('it can be printed') of the major superior before publication.
[5] In the context of canonizations, the phrase is used as an order from the Vatican that "nothing hinders" an investigation of a possible saint's life.
[6] Once this order is given, a diocesan or eparchial tribunal can be formed to investigate the life of the candidate, furthering the process of possible canonization.