1. Disapproval of or the minimization of something or someone: There was considerable deprecation regarding the use of company funds for political purposes.

Elaine said she didn't mean to deprecate Dudley's accomplishments as an author, but there weren't very many who purchased his book.

2. A prayer meant to avert or to remove some evil or disaster: Adam had deprecations in his nightly prayers to God to help people who were caught in the tornado.