Catechism of the Catholic Church §2807 — excerpt
The term "to hallow" is to be understood here not primarily in its causative sense (only God hallows, makes holy), but above all in an evaluative sense: to recognize as holy, to treat in a holy way.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.